Glossary of lichen terms

This glossary provides an overview of terms used in the description of lichens, composite organisms arising from algae or cyanobacteria living symbiotically among filaments of multiple fungus species.^[1][2]

Erik Acharius

Erik Acharius, known as the "father of lichenology," coined many lichen terms still in use today around the turn of the 18th century. Before that, only a couple of lichen-specific terms had been proposed. Johann Dillenius introduced scyphus in 1742 to describe the cup-shaped structures associated with genus Cladonia, while in 1794 Michel Adanson used lirella for the furrowed fruitbodies of the genus Graphis. Acharius introduced numerous terms to describe lichen structures, including apothecium, cephalodium, cyphellae, podetium, proper margin, soredium, and thallus. In 1825, Friedrich Wallroth published the first of his multi-volume work Naturgeschichte der Flechten ("Natural History of Lichens"), in which he proposed an alternative terminology based largely on roots from the Greek language. His work, presented as an alternative to that of Acharius (of whom he was critical) was not well received, and the only terms he proposed to gain widespread acceptance were epi- and hypophloeodal, hetero- and homoiomerous, and gonidium, the last of which remained in use until the 1960s.^[3] Until about 1850, there were 21 terms for features of the lichen thallus that remain in use today.^[3]

The increasing availability of the optical microscope as an aid to identifying and characterizing lichens led to the creation of new terms to describe structures that were previously too small to be visualized. Contributions were made by Julius von Flotow (e.g. epithecium), Edmond Tulasne (e.g pycnidium), and William Nylander (e.g. pseudocyphella, thecium). Gustav Wilhelm Körber, an early proponent of using spore structure as a character in lichen taxonomy, introduced amphithecium, muriform, and "polari-dyblastae", later anglicized to "polari-bilocular" and then shortened to polarilocular.^[4] In the next five decades that followed, many other additions were made to the repertoire of lichen terms, subsequent to the increased understanding of lichen anatomy and physiology made possible by microscopy. For whatever reasons, there were not any new terms (still currently used) introduced from the period 1906 to 1945, when Gustaf Einar Du Rietz proposed replacing epi- and hypothecium with epi- and subhymenium; all four terms remain in use.^[4] In some cases, older terminology became obsolete as better understanding of the nature of the fungal–algal relationship led to changes in their terminology. For example, after Gunnar Degelius objected to the use of gonidia for the algal partner, George Scott proposed the use of mycobiont and phycobiont for lichen components, recommendations that were generally accepted by lichenologists.^[5]

This glossary includes terms defining features of lichens unique to their composite nature, such as the major components the two major components of lichens (mycobiont and photobiont); specialized structures in lichen physiology; descriptors of types of lichens; two- and three-dimensional shapes used to describe spores and other lichen structures; terms of position and shape; prefixes and suffixes commonly used to form lichen terms; terminology used in methods for the chemical identification of lichens; the names of 22 standard insoluble lichen pigments and their associated reference species; and "everyday" words that have a specialized meaning in lichenology. The list also includes a few historical terms that have been supplanted or are now considered obsolete. Familiarity with these terms is helpful for understanding older literature in the field.

A

Thelomma santessonii is a crustose, areolate lichen.

a-

Also an-. A prefix meaning "not having" or "without".^[6]

ab-

A prefix meaning "positioned away from".^[6]

abortive

Referring to a developmental process in lichens where certain structures, such as spores or reproductive organs, fail to reach full development or maturity, often resulting in non-viable or malformed structures.^[7]

abraded

Having a worn or eroded thallus surface.^[8]

accessory substance

A lichen product that is sometimes present, sometimes not present in a species. In literature, these are usually indicated with a ± symbol, e.g. ±usnic acid.^[9]

-aceae

A suffix used to indicate the taxonomic rank of family.^[10]

-aceous

A suffix used to indicate a relation or similarity to something.^[10]

acervulate

Shaped like a saucer.^[11]

An acicular spore of Bacidia schweinitzii

acicular

Also aciculiform. Needle-shaped; long and slender with a taper at both ends. Typically used to describe spore shape.^[12]

acro-

Also acr-. A prefix used to indicate that something is positioned on the end or the upper part.^[13]

acrogenous

Developing on the apex of a structure.^[14]

acroton

A needle-shaped structure with lateral branches.^[8]

actinolichen

A lichen-like association between an actinobacterium (Streptomyces) and a green alga (Chlorella xantha).^[15]

acuminate

Gradually tapering to a point.^[16]

ad-

A prefix used to indicate positioning at the end or on an extremity.^[17]

adglutinated

Stuck together.^[18]

adnate

Having a tight attachment to a surface.^[19]

adventive branching

Referring to fruticose lichens, a branching pattern that is unusual or abnormal, like that which sometimes occurs after the original branches are damaged in Cladonia.^[8]

-al

A suffix used to indicate a relation to, or having the form and character of something.^[20]

Alectoria sarmentosa, Bryoria capillaris, and Sulcaria isidiifera are examples of alectorioid lichens.

alectorioid lichen

An informal growth form category used for lichens that are fruticose, typically with beard-like thalli that are pendant or clustered; this group of features is characteristic of lichens now classified in the genera Alectoria, Bryoria, Oropogon, Pseudephebe, and Sulcaria.^[21]

algal layer

Also photobiont layer.^[22] The layer of tissue in a heteromerous lichen thallus that contains the photobiont; it is typically located between the upper cortex and the medulla.^[23]

alcobiosis

Plural alcobioses. A form of symbiosis involving algae and corticioid fungi, primarily occurring on bark and wood surfaces. In this relationship, algae form a layer beneath the fungal basidiomata—structures akin to the photobiont layer in lichens. This association, unlike in lichens, does not render the fungal partner nutritionally dependent on the algae, thus all involved fungal species are capable of surviving without the algal partner. Alcobiosis represents a diverse interaction, seen in various stages of coevolution, involving multiple species across the Agaricomycetes fungal group and three algal species from the class Trebouxiophyceae.^[24]

alveolate

Used to describe a surface that has a pattern similar to a honeycomb (i.e. with more or less 6-sided hollows), where the surface appears to be composed of small pits or cavities like alveoli.^[25] Compare: faveolate, foveolate, scrobiculate.

amphi-

A prefix used to indicate on both sides, or on all sides.^[26]

amphithecium

Plural amphithecia. The thalline margin of a lecanorine apothecium;^[27] equivalent to the thalline exciple.^[28] The amphithecium usually contains algal cells.^[22] The term was coined by Wilhelm Körber in 1855, but languished in obscurity until 1898, when Otto Darbishire used it in a monograph of the genus Roccella.^[29]

ampliotremoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Ampliotremoid lichens have prominent apothecia with wide pores, black walls (viewed in microscopic section), and a smooth, more or less shiny thallus; this morphotype occurs in the genera Ampliotrema and Ocellularia.^[30]

ampulliform

Bottle-shaped, i.e., with a narrow neck and swollen base.^[31]

amyloid

Main article: Amyloid (mycology)

Turn a purple or blue color upon reaction with Melzer's reagent.^[32]

Cross section of an apothecium of the lichen Amandinea punctata. The exciple is pigmented dark brown, the epihymenium is brown, and the algal cells are green; asci (containing ascospores) are visible in the hyaline hymenium.

anisotomic

Also anisotomous.^[33] Having branches of unequal length;^[34] if the branching is anisotomic, one branch is typically stouter than the other, forming a main stem while the other appears like a lateral branch, as in the species Alectoria ochroleuca.^[33] Contrast: dichotomous.

annulotremoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Annulotremoid lichens have prominent apothecia with wide pores, pores with an inner ring, and a smooth, more or less shiny thallus; this morphotype occurs in the genera Myriotrema and Thelotrema.^[30]

anticlinal

Perpendicular to a surface;^[35] used to refer to hyphal alignment.

apical

Located at the highest point (the apex), the tip, or the end of something.^[36]

apiculate

Having a short projection (an apicule) at one end; typically used to describe spore morphology.^[37]

apothecium

Plural apothecia. A type of ascocarp that is open, saucer-shaped or cup-shaped, and in which the hymenium is exposed at maturity.^[38] The term was first used by Erik Acharius in 1803.^[3]

appressed

Lying flat; flattened down on a surface.^[39]

arachnoid

Also araneose, araneous.^[40] Having a cobweb-like form, like that of the irregularly oriented and loosely interwoven hyphae of the medullary layer of some lichens.^[41]

Arceutina-yellow

A pale yellow insoluble lichen pigment, associated with the reference species Bacidia arceutina.^[42]

arcuate

A shape or structure that is curved or arched like a bow.^[43]

ardella

Plural ardelae. A type of apothecium, typical of lichens in the family Arthoniaceae, which is small and round. Elongated ardellae are called lirellae.^[44] The term was first used by William Allport Leighton in 1854, who described an ardella as resembling a "sprinkled spot".^[4]

Closeup of some areolae and lecideine apothecia of Porpidia flavocaerulescens

areole

Plural areolae. A small area, typically rounded to polygonal or irregular in shape, and often with a distinct texture. In a lichen thallus, the areolae are often separated from the rest of the thallus by fissures or cracks.^[45]

areolate

Also areolar. The condition of being made of or covered with areolae, such as the areolate lichens.^[45]

Arnoldiana-brown

A reddish-brown insoluble lichen pigment, associated with the reference species Bacidina arnoldiana.^[46]

ascigerous

Having asci.^[47]

asco-

A prefix meaning "ascus".^[47]

ascocarp

Main article: Ascocarp

Also ascoma, plural ascomata. The fruiting body of an ascomycete fungus, containing the asci and ascospores.^[48]

ascoconidium

Plural ascoconidia. A conidium that is formed directly from an ascospore.^[49]

ascogenous

Also ascogenic. Producing or supporting the growth of an ascus.^[47]

ascolichen

A lichen in which the fungal partner (the mycobiont) is a member of the Ascomycota. About 98% of lichens are ascolichens.^[50] See related: basidiolichen.

Asci and ascospores of the lichenicolous fungus Opegrapha physciaria; 1000x magnification

ascospore

A sexual, haploid spore produced in an ascus.^[51]

ascus

Main article: Ascus

Plural asci. A sexual, fungal spore-bearing structure, typically sac-like.^[52]

aseptate

Lacking septa.^[47]

aspicilioid

Referring to lecanorine apothecia that are (at least initially) partially to completely immersed in the thallus.^[53]

astomate

Also astomous. Lacking an opening, or ostiole.^[47]

astrothelioid

Referring to a type of ascospore morphology prevalent in the genus Astrothelium; characterized by thick-walled distosepta and diamond-shaped lumina.^[54]

-ate

A suffix, added to nouns, used to indicate having the appearance or characteristics of that noun.^[55]

Atra-brown

A matt brown insoluble lichen pigment, associated with the reference species Opegrapha atra.^[56]

Atra-red

A dark red insoluble lichen pigment, associated with the reference species Tephromela atra.^[57]

aulaxinoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus structure. This term refers to a morphotype of lichen where the apothecia are partially embedded and partially protruding, having a dark, hardened thalline margin that forms irregular cracks. This morphotype is uniquely seen in "Thelotrema" dislaceratum, a species with uncertain taxonomic placement.^[58]

B

Lichenomphalia umbellifera (left) and Cora glabrata (right) are examples of basidiolichens.

bacillar

Also bacilar, bacilliform, baculate, baculiform. Shaped like a small rod, typically with a length:width ratio of about 3:1.^[59]

Bagliettoana-brown

A pale to brownish-green insoluble lichen pigment, associated with the reference species Bacidia bagliettoana.^[60]

basidiolichen

Main article: Basidiolichen

A lichen in which the fungal partner (the mycobiont) is a member of the Basidiomycota. About 0.4% of lichens are basidiolichens.^[50] See related: ascolichen.

bi-

A prefix meaning two or twice.^[61]

biatorine

A type of lecideine apothecium with a soft, light-colored (not carbonized) margin, like those in genus Biatorella.^[61]

bifurcate

Divided into two parts or branches.^[62] See related: dichotomous.

bifusiform

Referring to a shape or structure that is elongated and tapers at both ends, with a constriction or narrowing in the middle.^[18] See related: fusiform.

biguttulate

Containing two oil droplets (guttules).^[63]

bilabiate

Referring to a type of ascus in which the ectotunica splits at the top and exposes the endotunica by forming an opening with a lip on each side; bilabiate asci occur in the genus Pertusaria.^[63]

bipartite lichen

A lichen with a two-partner symbiotic association of mycobiont and photobiont.^[64] See related: tripartite lichen.

bipolar lichen

A lichen that occurs in polar areas of both the Northern and Southern Hemispheres.^[65]

biseriate

Lined up in two parallel rows.^[66]

bitunicate

Also defined: endotunica, ectotunica. A type of ascus that has two functional layers, the internal layer, the endotunica, and the external layer, the ectotunica. Bitunicate asci are characteristic of the historical class Loculoascomycetes.^[67]

blastidium

Plural blastidia. A rounded granule-like propagule containing mycobiont and photobiont, produced from the thallus margin by budding; subsequent blastidia are formed from the tips of the previous ones.^[11][68] The term was introduced by Josef Poelt in 1980.^[69]

borderline lichen

A symbiotic interaction where either green algae or cyanobacteria are enveloped by fungal tissue, but without forming the discrete layers that occur in most lichens.^[70]

botryose

Resembling rounded, bead-like structures or clusters resembling grapes.^[43]

Usnea angulata is a fruticose lichen with ridged branches.

branch

A lateral growth of the main stem of a thallus in usneoid lichens; various features of a branch are diagnostically valuable in distinguishing species.^[71]

branchlet

A small branch.^[72]

bryophilous lichen

Main article: Bryophilous lichen

Also defined: hepaticolous lichen; muscicolous lichen. A lichen that grows on a moss or liverwort – i.e. on a bryophyte.^[73] A hepaticolous lichen is found only on liverworts, while a muscicolous lichen is found only on mosses.^[74][75]

bullate

Having blister-like or bubble-like swellings on a surface.^[76]

byssoid

Having the texture of cotton; made of loosely intertwined hyphae.^[77] See related: arachnoid, floccose.

Contents: 

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C

The prominent dark cephalodia on the surface of Peltigera venosa contain cyanobacteria.

C test

A spot test that uses a solution of bleach (sodium hypochlorite) as a reagent to check for the presence of certain lichen products.^[78]

Caesiocinerea-brown

An insoluble lichen pigment, colored olive to sordid green to black, associated with the reference species Aspicilia caesiocinerea.^[60]

caesious

A bluish-gray or bluish-green coloration.^[43]

caespitose

Also caespitous, cespitose.^[79] Growing in dense clusters or tufts, often used to describe fungi that arise from a common base or grow closely together without fusing.^[18]

calcicolous lichen

A lichen that grows on substrates rich in calcium carbonate, such as calcareous or gypseous rocks or soil.^[80]

calcifuge

A lichen that prefers acidic soils and tends to avoid, or is intolerant of, alkaline conditions often associated with high calcium carbonate content; opposite of calcicole.^[81]

campylidium

Plural campylidia. A helmet-shaped conidioma. They are found in several genera of tropical foliicolous lichens, such as Badimia, Loflammia, and Sporopodium.^[82] The term was introduced by Johannes Müller Argoviensis in 1881.^[5]

Campylidia of the foliicolous lichen Badimiella pteridophila

canaliculate

Having one or more longitudinal grooves or channels.^[83]

capitate

Having a well-formed head, usually spherical or hemispherical in shape.^[68] See related: fuscocapitate.

capitulum

Plural capitula; also sphaeridium/sphaeridia. A more-or-less spherical or cup-shaped apothecium on the top of a stalk, found in the genera Calicium and Chaenotheca.^[84][68] See related: mazaedium.

carbonized

Also carbonised, carbonaceous. Blackened and brittle tissue resulting from the accumulation of pigments.^[85]

cariose

A lichen thallus or structure that is cracked, split, spongy, or otherwise decayed or in a state of disintegration.^[43]

cartilaginous

Also cartilagineus. A term used to describe the texture of certain parts of a lichen. Cartilaginous structures have a texture similar to animal cartilage – firm but somewhat pliable, not brittle or soft.^[86]

cataphysis

See pseudoparaphysis.

The squamulose species Catapyrenium boccanum, seen here growing in a depression of a calcareous rock, is a catapyrenioid lichen.

catapyrenioid lichen

A member of the Verrucariaceae that is squamulose, has simple ascospores (without any septa), and lacks algae in the hymenium; historically classified in the genus Catapyrenium.^[87]

catenate

Arranged in chains or end-to-end; refers to spore arrangement.^[88]

caudate

Having a tail or tail-like appendage.^[89]

cavernula

Plural cavernulae. A small hollow or cavity; used to refer to the holes in the lower cortex of the genus Cavernularia.^[90]

central axis

Also chondroid axis. The cartilage-like central core in the branches of usneoid lichens, made of longitudinally arranged hyphae.^[71] The term "chondroid axis" was first used by William Nylander in 1858.^[4]

cephalodium

Main article: Cephalodium

Plural cephalodia. A small gall-like structure that contains cyanobacteria, found in some lichens. These structures can be located on the lichen's upper or lower surface, or within the thallus itself.^[68] These structures are found in most lichens that contain both algal and cyanobacterial photobionts.^[91] The term was first used by Erik Acharius in 1803.^[3]

cerebriform

Having a surface texture that is deeply wrinkled or convoluted in a manner resembling the structure of a brain. The term is used to characterize the appearance of certain lichens with a complex, highly folded thallus.^[92]

cetrarioid lichen

An informal growth form category used for lichens with erect, foliose thalli, and apothecia and pycnidia on the margins of the lobes; characteristic of lichens previously classified in the genus Cetraria (in the broad sense).^[93]

chalaroplectenchyma

Plural chalaroplectenchymata. A type of plectenchyma comprising loosely interwoven hyphae with holes; found in the medulla of some lichens.^[92]

character

A distinguishing feature that is characteristic for an organism; equivalent to phenotypic trait.^[92]

chasmoendolith

Also chasmoendolithic. A type of organism, typically a lichen or fungus, that lives within cracks and fissures of rocks.^[94] See related: endolith.

checklist

A list of all of the species (sometimes including subspecies, varieties and forms) that occur within a particular region.^[95]

chemosyndrome

A set of lichen products produced by a species; this typically includes one or more major compounds and a set of biosynthetically related minor compounds.^[96]

chemotype

Main article: Chemotype

Chemically differing types of a species with the same morphological characteristics, of no or unknown taxonomic significance.^[9]

Chlorococcum infusionum, depicted in this 1843 illustration by Giuseppe Giovanni Antonio Meneghini, is a typical chlorococcoid green alga.

chlorococcoid

A term describing green algae with a coccoid shape.^[97]

chondroid axis

See central axis.

chroodiscoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus structure. Chroodiscoid lichens have open apothecia with recurved lobules and a smooth and more or less shiny thallus; this morphotype occurs in the genera Acanthotrema and Chapsa.^[30]

cilium

Plural cilia. Fine, hair-like outgrowths of the thallus or apothecium, common in foliose and fruticose lichens.^[68]

ciliate

Having cilia.^[98]

Cinereorufa-green

A green to turquoise insoluble lichen pigment, associated with the reference species Schaereria cinereorufa.^[99]

citriform

A shape or form that resembles a lemon or citrus fruit. The term is used to describe structures, particularly ascospores or other components of a lichen, that have an elongated, oval shape with tapered ends.^[100]

CK test

A seldom-used spot test performed with an application of C followed immediately by K.^[101]

cladoniiform lichen

Also cladoniform lichen, dimorphic lichen. Also defined: primary thallus and secondary thallus. A lichen with a two-fold growth form that includes both a crustose, squamulose, or foliose form and a fruticose form; the thallus differentiates into both horizontal (primary thallus) and vertical (secondary thallus, or podetium) structures. Cladoniiform lichens occur in the families Cladoniaceae and Baeomycetaceae.^[102]

clavate

Also claviform. A shape resembling a club, broader at one end and tapering towards the other; typically used to refer to ascospores and asci.^[103]

clypeate

See peltate.

coalescent

Also coalesced. Growing together to form one mass.^[104]

coccoid

Spherical; resembling a coccus.^[105]

complanate

Flat and smooth.^[106]

concolorous

Having the same color throughout.^[107]

confervoid

Appearing loosely filamentous or thread-like.^[43]

confluent

Joining together, blending into one.^[107]

Microscopic view of the radially arranged conidia in a conidiophore from Minutoexcipula, a lichenicolous fungus; the inset shows the fungus (visible as black spots) parasitizing its host, a crustose lichen in genus Pertusaria.

conidiophore

A specialized hyphal structure that produces and bears conidia.^[108]

conidium

Main article: Conidium

Plural conidia. Also conidiospore. A fungal asexual spore produced by mitosis in specialized structures such as pycnidia and campylidia.^[109][110]

conglutinate

Also conglutinated. Stuck or glued together; usually applied to hyphae or paraphyses.^[111]

consoredium

An aggregation or cluster of incompletely separated soredia.^[112] The term was introduced by Tor Tønsberg in 1992.^[113]

coralloid

Highly branched, similar to a coral in form.^[114]

coriacellate

With a somewhat leathery (coriaceous) texture.^[115]

coriaceous

With a leathery texture.^[115]

corrugate

Wrinkled; with alternate furrows and ridges.^[116]

cortex

Main article: Cortex (botany)

The lichen's outer layer(s), made up of tightly woven fungal filaments.^[109]

corticate

Having a cortex.^[116]

corticolous lichen

Main article: Corticolous lichen

A lichen that grows on bark.^[73]

crateriform

Shaped like a bowl or a crater; hemispherical and concave.^[117]

crenate

Having a scalloped or round-toothed edge.^[118]

crenulate

Having a finely scalloped edge; similar to crenate but with smaller notches.^[119]

cruentodiscoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Cruentodiscoid lichens have open apothecia with erect lobules and a pigmented disc, and a smooth, more or less shiny thallus; this morphotype occurs in the genus Chapsa.^[30]

crustose

Main article: Crustose lichen

A form of growth where the lichen is pressed so tightly against the substrate upon which it grows that it is impossible to remove without destroying either it or part of the substrate. Crustose lichens have a cortex only on their upper surface.^[120]

cryptoendolith

Also cryptoendolithic. A type of organism, particularly certain lichens and fungi, that live inside rocks or in the microscopic spaces within the mineral grains of rocks.^[94] See related: endolith.

cryptolecanorine

A lecanorine apothecium that is mostly immersed in the thallus, with an indistinct thalline margin.^[121]

cryptothalline

Pertaining to a type of lichen thallus that is largely hidden or immersed within the substrate, making it barely visible or entirely concealed.^[122] See related: chasmoendolithic, cryptoendolithic, endolithic. Contrast: euthalline.

crystallocumuli

Punctiform or elongated agglomerations of oxalate crystals that are dispersed over the thallus; associated with the family Porinaceae.^[123] See related: crystallostratum.

crystallostratum

A continuous layer of oxalate crystals embedded in the thallus, associated with the family Porinaceae. The term was introduced by Josef Hafellner and Klaus Kalb in 1995.^[124] See related: crystallocumuli.

cuculate

Hood-shaped.^[125]

cupulate

Cup-shaped.^[126]

cuneate

Also cuneiform. Wedge-shaped; with one end thinner than the other.^[127]

cyanolichen

Main article: Cyanolichen

A lichen in which the photobiont is a cyanobacteria.^[128]

Closeup of the thallus underside of a Sticta lichen showing its crater-like cyphellae; scale bar = 1 mm

cyphella

Plural cyphellae. A sharply defined, rounded, ovate, or shapeless pore in the lower thallus surface (typically the lower cortex), which is lined with a "pseudocortex" made of loosely connected, non-gelatinized hyphae (often with globular cells, formed from the medulla) and bounded by a pale ring; known to occur in the genera Sticta and Oropogon.^[129] The term was first used by Erik Acharius in 1799.^[3]

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D

dactyloid

See digitate.

decorticate

Having had a cortex that has been removed or disintegrated.^[130] See related: ecorticate.

decumbent

Lying flat on a substrate with the edges curled up.^[131]

dendritic

Irregularly branched, like a tree.^[132]

dentate

Having a toothlike or serrated edge.^[133]

denticulate

Having small tooth-like projections or serrations along the edge.^[134]

dextrinoid

A chemical property referring to a substance's ability to turn reddish-brown in the presence of Melzer's reagent or iodine due to the presence of dextrins. This color reaction is also called hemiamyloid or pseudoamyloid.^[135]

determinate

Having well-defined or clearly marked edges.^[136] Contrast: effuse.

diagnosis

A brief account of a taxon describing the essential characteristics that distinguish it from its relatives.^[137]

diahypha

Plural diahyphae. A type of conidium formed from hyphae that split apically in several branches, with prominent constrictions at the septa, resulting in the appearance of chain links; found in the family Gomphillaceae.^[138][139]

diaspore

Main article: Diaspore (botany)

A sexual or asexual propagule used for dispersal; in lichens, usually used to refer to isidia and soredia.^[137]

dichotomous

Branching into two equal parts.^[133] See related: bifurcate. Contrast: anisotomic.

diffuse

Spread out and scattered without any definite boundary or margin.^[140] See related: effuse. Contrast: determinate.

The thallus of the fruticose Arctic finger lichen (Dactylina arctica) consists of mostly unbranched, digitate stalks.^[141]

digitate

Also dactyloid, dactyliform, digitiform. Having finger-like outgrowths.^[142]

dimidiate

A structure that is divided into two unequal halves, often appearing as half-circles; in lichenology the term is often applied to the excipulum.^[43]

dimorphic lichen

See cladoniiform lichen.

discoid

Also: disciform. A shape that is flat and circular, resembling a disk. In lichenology, this term often refers to the apothecia of lichens that have a flat, disk-like shape.^[143]

discolichen

A grouping of ascolichens that produce disk-like apothecia, somewhat analogous to the fungal Discomycetes; the term applies to the majority of lichens.^[144]

discothecium

Plural discothecia. The fruiting body of certain types of lichens, with cylindrical, bitunicate asci. It is distinguished from a hysterothecium, which is another type of fruiting body, by not opening through a slit but by expanding the asci to weather or push apart the typically thin upper stromatal layer.^[145] The term was introduced by Richard P. Korf in 1962.^[146]

disk

Also: disc. The curved or flat upper surface of the hymenium in an apothecium, often pigmented and surrounded by a margin or rim.^[143]

distal

Positioned away from a point of origin or from the center of a body.^[147]

distoseptum

Plural distosepta. A type of septum found in some conidia and ascospores, which is located within but distinct from the outer wall and surrounds the internal lumina. Structures with distosepta are said to be distoseptate.^[148]

doliiform

Barrel-shaped.^[149]

dome

See tholus.

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E

e-

A prefix meaning "not having" or "without".^[148]

eccentric

Also excentric. Displaced from the center.^[150]

echinate

Covered with spines or bristles.^[150]

echinulate

Covered with small spines or bristles.^[151]

ecorticate

Lacking bark, or a cortex.^[152]

ectal excipulum

See proper exciple.

ecto-

A prefix meaning "outside" or "outer".^[153]

ectotunica

See bitunicate.

This saxicolous Dimelaena lichen has a placodioid growth form and an effigurate thallus outline.

effigurate

Referring to crustose, areolate lichens with marginal areoles that are extended and arranged radially;^[154] also defined more generally as "obscurely lobed".^[155][156]

effuse

Spread out and flat; used to describe the thallus of some crustose lichens lacking a well-defined outline.^[157] Contrast: determinate.

eguttulate

Lacking oil droplets (guttules).^[158]

Elachista-brown

A fuscous brown insoluble lichen pigment, associated with the reference species Micarea elachista.^[56]

ellipsoid

Main article: ellipsoid

An object appearing approximately elliptical in longitudinal section and circular in cross-section; often used to refer to spore shape.^[159]

emarginate

Also immarginate.^[160] Lacking a well-defined border or edge.^[159] When referring to apothecia, it means lacking a thalline exciple, or a raised proper exciple.^[161] See related: effuse, marginate.

endo-

Also end-, ecto-, ect-. A prefix meaning "inside" or "inner".^[162][163]

endocarpic

Also endocarpinoid. Referring to lichens with perithecia that are sunk into the tissues of the thallus, such as seen in the genera Endocarpon and Dermatocarpon.^[164]

endolichenic fungus

A fungus that lives within the thallus of a lichen without producing any visible symptoms of disease; these fungi are transmitted horizontally.^[165]

Lecidea laboriosa is an endolithic lichen; the thallus, hardly visible, grows under and around the rock crystals, while the apothecia are visible on the surface.

endolith

Also endolithic. A crustose lichen that grows in the interior of rocks (under and around the rock crystals), typically with little or no visible thallus on the outer rock surface.^[166] Contrast: epilithic. See related: chasmoendolith, cryptoendolith, euendolith.

endophloeodal

Also endophloeodic, endophloeic, endophloic. Refers to crustose lichens whose thalli are more or less immersed in tree bark.^[167] Contrast: epiphloedal.

endotunica

See bitunicate.

entire

Refers to margins or edges of lichen structures (such as apothecia, lobes, or thalli) that are smooth and unbroken, without any notches, teeth, or irregularities.^[168]

epi-

Also ep-. A prefix meaning "upon" or "above".^[169][170]

epibryophyllous

Also epibryophytic. Referring to organisms, particularly lichens or fungi, that grow on the surface of mosses (bryophytes).^[169]

epicortex

A thin layer of polysaccharides that is present on the surface of the cortex in some parmelioid lichens.^[170]

epihymenium

A thin tissue layer of interwoven hyphae situated directly above the hymenium, which can contain pigments and sometimes plays a role in the coloration of the lichen.^[171] Compare: epithecium.

epilithic

Also petricolous, rupicolous, saxicolous. A crustose lichen that grows on the surface of rocks.^[166] Contrast: endolithic.

epinecral layer

A layer of dead hyphae with indistinct lumina found near the cortex and above the algal layer.^[172] See related: hyponecral layer.

epiphloedal

Also epiphloeodal, epiphloeodic, epiphloic.^[173][174] Growing on the surface of bark.^[171] Contrast: endophloeodal.

epipsamma

A region of granule-like, often pigmented material, that permeates the upper parts of hymenium but is distinct from the epithecium; associated with the genus Rhizocarpon.^[175] The term was coined by Josef Poelt in 1969.^[5]

epithecium

Plural epithecia. Tissue on the top of an apothecium (above the hymenium) formed from the coalesced tips of projecting paraphyses.^[176] The term was first used by Julius von Flotow in 1851.^[4]

epruinose

Lacking priuna.^[177]

erumpent

Also perrumpent. Breaking through a surface.^[178] A more precise definition has been suggested by Aptroot and Lücking, who propose that the term applies to ascomata and pseudostromata that are more than 1/2 to 3/4 above the level of the thallus.^[179]

esorediate

Also esorediose. Lacking soredia.^[180]

eucortex

Plural eucortices or eucortexes. A cortex made of well-differentiated tissue.^[181] Another sense of the term, used by Josef Poelt, refers to cortical tissue made entirely of fungal cells originating from a cambium-like tissue layer in or above the algal layer.^[182] The term eucortex was first used by Gunnar Degelius in 1954.^[5]

euendolith

Also euendolithic. A type of organism, often a lichen or microbe, that actively bores into and resides within the mineral matrix of rocks or other hard substrates.^[94] See related: endolithic.

euthalline

Describing a type of lichen thallus that is clearly visible and well-developed on the surface of the substrate.^[122] See related: epilithic. Contrast: cryptothalline.

evanescent

Lasting a short time.^[156]

excipulum thallinum

See thalline margin.

A sample page from Ludwig Schaerer's exsiccata series Lichenes Helvetici (Swiss lichens), published in 26 fascicles from 1823 to 1852.

exsiccatum

Main article: exsiccata

Plural exsiccata, exsiccatae, exsiccati. A dried and labeled herbarium specimen, often part of a numbered set.^[183]

excipulum

Also exciple. Plural excipula. The cup-shaped or ring-shaped layer of tissue supporting the hymenium in an apothecium; this tissue sometimes develops into a distinct margin, as in the lecanorine apothecia.^[184] See related: proper margin, thallin margin.

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F

fabiform

Bean-shaped.^[185]

facultatively lichenicolous

A fungus species that is commonly collected from lichens (i.e., it is lichenicolous) but is also capable of living on non-lichen substrates.^[186]

falcate

Also falciform, lunate. Thin and curved with pointed ends, like a scythe or sickle.^[187]

farinaceous

Also farinose. Covered with a mealy powder; the podetia of Cladonia deformis are covered with farinose soredia.^[188]

The fruticose lichen Ramalina farinacea has a thallus made of fasciate branches.

fasciate

Also fasciated. Having a ribbon-like or band-like structure, such as the thallus of some fruticose lichens.^[189]

fascicle

A bundle or cluster; can be used to refer to asci, conidiophores, hyphae, etc.^[189]

fasciculate

Arranged in bundles or clusters.^[190]

Pulchrocladia retipora has fenestrate lobes.

fastigiate cortex

A region of the cortex where the hyphae are aligned perpendicularly to the main axis of the thallus.^[190] The term was first used by Auguste-Marie Hue in 1906.^[5] See related: palisade cell.

faveolate

Pitted with large, deep depressions that are narrowly separated by sharp ridges.^[191] Compare: alveolate, foveolate, scrobiculate.

fenestrate

Having perforations or gaps arranged in a regular pattern.^[192]

-fer

Also -ferous. A suffix meaning to carry or produce.^[193]

fibercle

A scar on lichen thalli resulting from the breaking of attached fibrils; associated with the genus Usnea.^[193]

fibril

A tiny fibre; when referring to the genus Usnea, it means short branches that are perpendicular to the main branches.^[194]

fibrillose

Covered with silky fibres.^[195]

filiform

Thread-like; fine and slender.^[196]

fimbriate

Having hairs or fibres on the margin.^[197] See related: arachnoid, fimbrillate.

fimbrillate

Delicately fimbriate; bordered with minute fringe.^[197]

fissitunicate

A form of bitunicate ascus in which the flexible layers of the inner wall (the endotunica) and the more rigid layers of the outer wall (the ectotunica) are physically separated; as a consequence, the inner walls extend past the outer walls before the spores are released.^[198]

fissurine

Also fissurate. A term used characterize a structure or surface displaying a pattern of narrow, elongated cracks or fissures.^[199]

fissurinoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus structure. This morphotype is somewhat similar to the chroodiscoid, but it differentiates by the way the apothecia open through irregular thallus cracks, finally resembling chroodiscoid apothecia. It often has a unique elongated form at maturity and can be seen in species such as Acanthotrema brasilianum and various Chapsa species.^[200]

fistular

Also fistulose. Tubular and hollow.^[201]

flabellate

Also flabelliform. Fan-shaped.^[202]

flexuous

Also flexuose. Bending or curving in alternate directions, like a zigzag.^[202]

floccose

Having the texture of loose cotton or wool.^[203]

Foliicolous lichens are those which grow on the surface of a plant leaf.

foliicolous lichen

Main article: Foliicolous lichen

Also epiphyllous lichen. A lichen that grows on a plant leaf.^[73]

foliole

A small leaf-like outgrowth from the thallus of a foliose lichen.^[204]

foliose

Main article: Foliose lichen

Leaf-like; a type of lichen thallus comprising numerous small leafy lobes, often extending in a roughly circular pattern from a center of growth, on a lower cortex that is attached to the substrate by rhizines or at a base.^[205][206]

forage lichen

Lichens that serve as important food sources for fauna. For example, species from the genera Alectoria, Bryoria, and Cladonia are winter forage lichens for caribou in northern North America.^[207][208]

foveate

Having pits or perforations.^[209]

foveolate

Pitted with small, deep depressions that are widely separated by a more or less even thallus.^[210] Compare: faveolate, scrobiculate.

friable

Main article: Friability

Readily crumbled or pulverized.^[211]

fruit wart

An informal term for a type of apothecium that has perithecioid (pertusariate or thelotremoid) characteristics.^[212]

fruticose

Main article: Fruticose lichen

A lichen with a shrub-like or hairy thallus attached to the substrate at a single point.^[202]

fruticulose

Also fruticulous . A smaller version of a fruticose lichen.^[202] See related: microlichen.

fulvous

An yellow-brown or tawny color.^[43]

funiculus

See umbilicate lichen.

funoid

Made of fibers or rope-like strands.^[43]

furcate

Forked.^[213]

furfuraceous

Covered with small flakes.^[213]

fuscocapitate

A term used to describe structures, such as hairs or other appendages, that have a dark or dusky-colored rounded tip or head.^[214]

fuscous

A dark, grayish-brown or grayish-black color.^[213][215]

fusiform

Main article: Fusiform

Tapered at both ends, like a spindle.^[213]

fuzzy coat

The outer gelatinous layer, also known as the g-layer, found on the exterior of an ascus, often exhibiting a gelatinous consistency and staining blue in iodine. Typically present in all asci, the fuzzy coat usually forms a thin layer along the ascus sides but may also appear as an apically thickened cap.^[216][217]

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G

Collema subflaccidum is a gelatinous lichen with a homoiomerous internal structure.

gelatinous lichen

A rubbery or jelly-like lichen with a cyanobacterial photobiont.^[218] See related: homoiomerous.

geniculate

Having a knee-like bend; applied to parts of hyphae and conidiophores where a bend forms due to directional changes during growth.^[219]

glabrescent

Becoming glabrous.^[220]

glabrous

Lacking hair or bristles; smooth.^[220]

glaucescentoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Glaucescentoid lichens have open apothecia with erect lobules, and a rough thallus containing crystals; this morphotype occurs in the species Leucodecton glaucescens.^[30]

glaucophaenoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Glaucophaenoid lichens have prominent apothecia with wide pores, pale walls (viewed in microscopic section), and a smooth and more or less shiny thallus; this morphotype occurs in the genus Myriotrema.^[30]

gleolichen

Also gloeolichen. A homoiomerous lichen with algal cells belonging to the genera Chroococcus, Gleocapsa, or other Chlorococcales; these algae have a mucilaginous capsule.^[221]

globose

Also globoid, globular. Approximately spherical.^[222]

glomerule

Plural glomeruli. A dense clump or aggregate of cells or spores.^[222]

Glypholecia scabra has glypholecideous lirellae

glypholecideous

Also glypholecine.^[223] Having especially labyrinth-like lirella, as in the genus Glypholecia.^[224]

gonidial layer

A now-obsolete, historical term for the algal layer in a lichen.^[225]

gonidium

Plural gonidia. A now-obsolete, historical term for a lichen photobiont.^[225] The term was first used by Friedrich Wallroth in 1825, and supplanted in the 1960s.^[3]

gonimium

Plural gonimia. A now-obsolete, historical term for a lichen cyanobiont.^[225]

Microscopic view of young goniocysts of Gabura borbonica formed at the lobe margins; scale bar = 20 μm

goniocyst

A vegetative propagule found in some tropical foliicolous lichens that consists of photobiont cells wrapped in mycobiont hyphae; it is similar in form to soredia, but it is made in a special organ called a goniocystangium.^[224] The term goniocyst was introduced by Johannes M. Norman in 1872.^[5]

goniocystangium

Plural goniocystangia. A special organ, found in some tropical foliicolous lichens, that produces goniocysts.^[224]

granular

Also granulate, granulose. Made of small particles (granules).^[226]

granule

An irregularly rounded grain-like particle.^[188]

graphid

A lichen with apothecia in the form of lirellae, as in the genus Graphis.^[188]

growth form

Main article: Lichen growth forms

A term for the general appearance (the habit) of a lichen.^[227]

grumose

Having a granular or crumbly texture or appearance.^[43]

guttulate

Referring to structures containing small oil droplets (guttules); often used to describe spores. More precisely, spores can be described as uni-, bi-, tri-, or multiguttulate.^[228]

Gyrodiscs on the thallus of Umbilicaria cylindrica

gyrodisc

An apothecium with concentric circles on the upper surface, as seen in the species Umbilicaria cylindrica.^[229] The term was first used by George Llano in 1950.^[5]

gyrose

Also gyrate. Curved backward and forward; with folds and undulations.^[230]

gyrotremoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Gyrotremoid lichens have open apothecia with recurved lobules, a disc that is pigmented with concentric rings, and a smooth, more or less shiny thallus; this morphotype occurs in the genus Gyrotrema.^[30]

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H

hafter

A flattened attachment point formed through direct contact of a lichen thallus to its substrate; associated with foliose and fruticose lichens that lack other attachment organs, such as Hypogymnia.^[231]

halonate

Also defined: halo. Referring to a spore that is surrounded by a transparent outer layer or a gelatinous, translucent sheath. This sheath is readily observed when the spore is stained with India ink, as the ink does not penetrate the mucilage of the sheath, creating a light-transparent halo that is visible against a blackened background.^[232][233]

hamathecium

Also interascal tissue. A term describing the hyphae and tissues that exist between the asci; examples include paraphyses, paraphysoids, pseudoparaphyses, periphysoids, and periphyses.^[234]

hapteron

Also hapter, plural haptera. An aerial attachment organ, made of highly adhesive hyphae, that helps secure a thallus to its substrate in some fruticose lichens, such as Cladonia, Ramalina, and Usnea.^[234]

hemiamyloid

See dextrinoid.

hepaticolous lichen

See bryophilous lichen.

Hertelii-green

A green to turquoise insoluble lichen pigment, associated with the reference species Biatora hertelii.^[57]

hetero-

Also heter-. A prefix meaning "other" or "different".^[235]

heterocyst

A specialized type of cell found in some cyanobacteria; heterocysts are thought to be involved in the fixation of nitrogen by the lichen thallus, as well as in the multiplication of cyanobacteria.^[236]

heteromerous

A lichen thallus that is organized into discrete layers or strata; the term applies to the majority of foliose, squamulose, and crustose lichens.^[237]

Phaeophyscia hirsuta is named for its hirsute lobe margins.

hirsute

Also hispid, strigose. Covered with hairs.^[238]

holdfast

Main article: Holdfast (biology)

A part of the thallus, usually near the base, that is adapted for attachment to the growing surface.^[239]

homo-

A prefix meaning "analogous", "similar", or "same".^[240]

homoiomerous

A lichen in which the cyanobiont partner (typically from genus Nostoc) is evenly distributed throughout the thallus; characteristic of gelatinous lichens such as Collema and Leptogium.^[241] The term was first used by Friedrich Wallroth in 1825.^[3]

hormocyst

Also hormocyte. Also defined: hormocystangium, plural hormocystangia. An asexual propagule, produced in a cup-shaped structure called the hormocystangium, comprising heavy, gelatinous fungal hyphae enclosing a few cyanobiont cells; these structures occur in some gelatinous lichens in the family Collemataceae.^[242] Both terms, hormocyst and hormocystangium, were introduced by Gunnar Degelius in 1945.^[5] According to one source, hormocyte and hormocytangium (spelled without the "s") are more accurate terms, because the cells (indicated by the ending -cyte) are not sexual propagules (which is implied by the ending -cyst).^[243]

hyaline

Main article: Hyaline

Transparent and colorless.^[244]

hymenium

Main article: Hymenium

The fertile tissue of the fruit body where spores are produced.^[245]

hypha

Main article: Hypha

Plural hyphae. A microscopic fungus filament comprising one or more cells surrounded by a tubular cell wall.^[246]

A hyphophore from the foliicolous lichen Tricharia santessonii

hyphophore

An erect, stalked, peltate, asexual spore-producing organ (sporophore) associated with tropical foliicolous lichens.^[247]

Hypnorum-blue

A dark blue to black insoluble lichen pigment, associated with the reference species Lecidea hypnorum.^[46]

hypo-

Also hyp-. A prefix meaning "beneath" or "under".^[248]

hypogymnioid lichen

An informal growth form category used for foliose lichens with lobes that are swollen, inflated, and lacking rhizines, combined with the presence of the substances atranorin in the upper cortex and physodic acid in the medulla. These features are characteristic of lichens in the genera Hypogymnia and Menegazzia.^[249]

hyponecral layer

A layer of dead hyphae with indistinct lumina found near the cortex and below the algal layer.^[172] See related: epinecral layer.

hypophloeodic

Also hypophloeodal. Refers to crustose lichens whose thalli are almost immersed in tree bark; characteristic of several species in the Thelenellaceae.^[250] The term was first used by Friedrich Wallroth in 1825.^[3] See related: endophloeodic.

hypothallus

The first hyphae to grow in a crustose lichen;^[251] often blackish in color, it is where rhizines originate.^[250] The term was first used by Elias Fries in 1831.^[4]

hypothecium

Plural hypothecia. A layer of tissue under the subhymenium in an apothecium; also used to refer more generally to all tissues under the hymenium.^[251] The term was first used by Carl von Martius in 1828.^[4]

hysterothecia

See lirella.

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I

I

An abbreviation for a solution of iodine crystals dissolved in aqueous potassium iodide and diluted to a light brown color.^[252]

imbricate

Also imbricated. Overlapping partially, like roof tiles; used to refer to lichen structures like scales, squamules, lobules, and lobes.^[253][160]

immaculate

Without spots.^[253]

immarginate

See emarginate.

immersed

Embedded or sunken into the surface; in lichens, often used to describe perithecia.^[253] A more precise definition has been suggested by Aptroot and Lücking, who propose that the term applies to ascomata and pseudostromata that are more than 3/4 beneath the level of the thallus.^[179]

incertae sedis

Main article: Incertae sedis

A term used for a taxon of uncertain, doubtful, or unknown classification.^[254]

incised

Having deep, sharp notches or cuts along the edges, often describing the margins of a lichen's thallus or apothecia.^[160]

imperforate

Lacking an opening.^[160]

inflated

Swollen or blown up, and hollow, like the lobes of genus Hypogymnia.^[255]

inspersed

Also defined: inspersion. Also inspers, interspersed. Terms used to describe the presence of minute, scattered oil droplets or granules within a tissue, typically observed in section with a compound microscope.^[256] An inspersion refers to the degree of obstruction caused by the sprinkling of small particles within different sections of a given structure.^[257]

Intrusa-yellow

A yellow insoluble lichen pigment, associated with the reference species Carbonea intrusa.^[42]

involucrellum

Plural involucrellae. The tissue of the outer part of a perithecium, often pigmented, surrounding the exciple.^[258]

Closeup of the pustulate isidia that are characteristic of Flavoparmelia baltimorensis; scale bar = 1 mm

isidiate

Having isidia.^[259]

isidiomorph

A structure that resembles an isidium, but is formed as an outgrowth of the medulla rather than the cortex; associated with soralia of species in the genus Usnea.^[260]

isidiotremoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Isidiotremoid lichens lack apothecia and have isidia, and a smooth, more or less shiny thallus; this morphotype occurs in the genera Myriotrema and Ocellularia.^[30]

isidium

Main article: Isidium

Plural isidia. A propagule that is an outgrowth of the thallus; it has a cortex and contains photobiont cells.^[259] The term was first used in the sense it is used now by Georg Meyer in 1825, and adopted by Elias Fries in 1831.^[3]

isodiametric

Having roughly equal dimensions in all directions, resulting in a roughly spherical or cube-like shape; often used to describe cells that are not elongated or flattened but maintain a uniform size across their width, height, and depth.^[261]

isotomic

Having branches of equal length.^[262]

isthmus

The narrow middle portion between the two locules of a polarilocular spore.^[263]

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J

juga

Plural jugae. A tiny carbonized structure made of hyphal tissue, visible as a black dot, line, or ridge, on or in a thallus; associated with the genus Verrucaria.^[264]

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K

K test

A spot test that uses a 10–25% solution of potassium hydroxide as a reagent to check for the presence of certain lichen products.^[265]

KC test

A spot test performed with an application of K followed immediately by C.^[266]

L

labriform

Shaped like or resembling a lip.^[267]

lacinia

Plural laciniae. A narrow lobe of a foliose lichen thallus.^[268]

laciniate

Also laciniated. Referring to an edge divided into delicate bands or narrow lobes.^[268]

lactophenol cotton blue

Main article: Lactophenol cotton blue

Also LCB. A histological stain commonly used to prepare semi-permanent slides. With this reagent, fungal hyphae stain blue, and algal cells stain deep blue to blue-green.^[101]

lacunose

Also lacunar, lacunous. A texture that appears pitted or containing gaps or holes, giving it a somewhat rough or uneven appearance.^[269]

lageniform

Flask-shaped; with a swollen base tapering to a narrow top.^[270]

lamella

Plural lamellae. In the genus Umbilicaria, lamellae are flattened plate- or strap-like structures that project downward from the thallus undersurface.^[271]

lamelloid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus structure. In this, apothecia are noticeably protruding and organized into several distinct, concentric rows of lobulate excipula. This morphotype is seen in species like Chapsa lamellifera.^[272]

laminal

All over the thallus surface, rather than in the center or on the margins.^[255] Contrast: marginal.

Comparison of the lecideine apothecia of Lecidea fuscoatra (left) and the lecanorine apothecia of Lecanora allophana (right)

Diagrammatic representation and comparison of cross sections of lecideine (left) and lecanorine (right) apothecia

Laurocerasi-brown

A reddish- or purplish-brown insoluble lichen pigment, associated with the reference species Bacidia laurocerasi.^[56]

lax

Loose, loosely woven, not compact; like the hyphae in the medulla.^[273]

lecanorine

Also lecanoroid. An apothecium in which the disk is surrounded by a pale thalline margin, which has both algal and fungal cells, as in the genus Lecanora. The term is also used more generally to refer to crustose lichens of the order Lecanorales that have rounded apothecia with thick, protruding margins.^[274]

lecideine

Also lecideoid. An apothecium in which the disk lacks a thalline margin, as in the genus Lecidea. The term is also used more generally to refer to apothecia with a blackened (carbonaeous) ring and a blackish disk.^[275]

leiodisk

Also leiodisc. A disk of an apothecia that is smooth and without folds or protrusions.^[276] The term was introduced by George Llano in 1950.^[5]

lepadinoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus structure. This morphotype describes lichens where apothecia are semi-embedded to prominently protruding and have a free excipulum and a distinctive double margin. The thalline margin bulges and remains whole, while the excipulum is prominent and wavy-lobed. Fibrillithecis halei, Leucodecton occultum, Myriotrema costaricense, and Thelotrema are examples of this morphotype.^[277]

leprocarpoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Leprocarpoid lichens have open apothecia with erect lobules and a mealy and more or less matte thallus; this morphotype occurs in the genus Chapsa.^[30]

The corticolous species Lepraria harrisiana, seen here as greenish powder on the tree trunk, is an example of a leprose lichen with an effuse and emarginate thallus.

leprose lichen

Main article: leprose lichen

A lichen made entirely of granular soredia, lacking a cortex.^[278]

Leptocline-brown

A dark red-brown insoluble lichen pigment, associated with the reference species Buellia leptocline.^[56]

Leptoclinoides-brown

A brown insoluble lichen pigment, associated with the reference species Hafellia leptoclinoides.^[56]

leptotremoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Leptotremoid lichens have immersed apothecia with small pores, and a rough thallus containing crystals; this morphotype occurs in the genus Leptotrema.^[30]

leucodectonoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Leucodectonoid lichens have closed apothecia with tiny pores, and a rough thallus containing crystals; this morphotype occurs in the genus Leucodecton.^[30]

lichen desert

A zone around a city or air pollution source that is devoid of foliose and fruticose lichens.^[279]

Lichenes

The name of a historical class that contained all of the lichen-forming fungi. This name was used when it was still erroneously believed that these fungi were quite separate from the non lichen-forming fungi; now obsolete.^[279]

lichenicolous lichen

Main article: Lichenicolous lichen

A lichen that grows on another lichen.^[73]

lichenin

Main article: lichenin

Also lichenan. A polymer of glucose that occurs in the cell walls of the hyphae of many species of lichen-forming fungi. It forms a red color when stained with iodine.^[280]

lichenometry

Main article: lichenometry

A dating technique that measures crustose lichen growth to estimate the amount of time a rock surface has been exposed.^[280]

lignicolous lichen

Main article: Lignicolous lichen

A lichen that grows on stripped wood (lignin) – that is, on bare wood rather than bark.^[73]

ligulate

Also liguliform, lingulate, lorate. Narrow and flat, with the form of a strap.^[281]

Closeup of the lirellae of Graphis desquamescens; scale bar = 0.5 mm

lirella

Plural lirellae. Also hysterothecia, lirelline apothecia. A linear ascocarp, which may be straight, curved, branched, or flexuous, with a longitudinal slit; characteristic of lichens in the genus Graphis.^[282] The term was first proposed by Michel Adanson in 1794.^[3]

lirellate

Also lirelliform. Having the form of lirellae.^[283]

litho-

A prefix meaning "stone" or "rock".^[284]

lithocortex

Cortex tissue made of closely compacted, agglutinated hyphae that forms a dense tissue layer.^[218]

lobate

Divided into lobes, such as the thallus of Lobaria scrobiculata.^[285]

lobe

A rounded or elongated projection of a thallus edge; in technical descriptions, it is measured from its widest point.^[255]

lobule

A small lobe originating from the edge or surface of a foliose lichen, typically the same color and character as the thallus.^[286]

lobulate

Having small lobes.^[287]

locule

Also loculus. A cavity or space.^[287]

lorate

See ligulate.

lumen

Plural lumina or lumens. An internal space or cavity in a structure, such as a cell, hypha, or septate spore.^[288]

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M

macrolichen

A lichen with a thallus large enough that its main characteristics can be identified without the use of viewing magnification; generally refers to foliose, squamulose, and fruticose species.^[289]

maculate

Covered with spots (maculae).^[290]

maniciform

Cuff-shaped; the term is used to describe soralia that break open to form a central perforation revealing a duct to the medullary cavity. Maniciform soralia occur in the genera Hypogymnia and Menegazzia.^[291]

marginal

On the thallus margins.^[292] Contrast: laminal.

The mazaediate ascomata of the shrub stubble lichen (Allocalicium adaequatum) rest atop short stalks.

marginate

Having a well-defined border or edge.^[293] Contrast: emarginate.

matte

Also: matt. A flat or non-reflective surface texture, lacking gloss or shine; contrast nitid.^[252]

mazaedium

Plural mazaedia. A powdery mass of ascospores and paraphyses formed by the disintegration of the asci in the ascomata of some lichens; associated with the order Caliciales.^[292] The term was first used by Erik Acharius in 1817.^[3]

medulla

Main article: Medulla (lichenology)

The internal tissue of a lichen thallus, located beneath the cortex and the photobiont layer, and usually made of loosely compacted hyphae.^[294]

medullary excipulum

See proper exciple.

Melaena-red

A purple insoluble lichen pigment, associated with the reference species Micarea melaena.^[295]

Melaenida-red

A purple insoluble lichen pigment, associated with the reference species Micarea melaenida.^[42]

melanotopelioid

A morphotype of corticolous thelotremoid lichens describing a type of apothecium structure resembling topeliopsidoid apothecia but characterized by a minimized thallus margin. The distinctive feature of melanotopelioid apothecia is the presence of "teeth" that are black and carbonized, at least on the external surface.^[296]

melanotremoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Melanotremoid lichens have prominent apothecia with wide pores and a black margin; pore filled with broad "stump" (columella); black walls (viewed in microscopic section); and a smooth, more or less shiny thallus. This morphotype occurs in the genera Melanotrema, Ocellularia, Clandestinotrema, and Trinathotrema.^[30]

micareiod

Referring to small chlorococcoid green algal photobionts that often occur in pairs, as in the genus Micarea.^[297]

microcrystallization

Main article: Microcrystallization

Also microcrystal test. A method used to identify some lichen products that involves re-crystallization on a microscope slide from a range of solvents and the formation of crystals with characteristic shapes; the crystals are examined microscopically for identification. Although this technique has largely been supplanted by the more reliable and sensitive technique of thin-layer chromatography, there are certain situations where it is still useful.^[298]

microlichen

A small lichen whose physical features cannot be distinguished without the aid of a 10X or greater viewing magnification;^[299] it generally refers to crustose and foliicolous species.^[300] The prefix "micro-" is also used to indicate small versions of particular growth forms, e.g. microfruticose or microfoliose.

microphylline

Having minute lobules.^[267]

moniliform

Also monilioid. Having a form resembling a string of beads.^[301]

monophyllous

Referring to the thallus of a foliose lichen that has only a single lobe.^[302]

multi-

A prefix meaning "more than one" or "many".^[303]

multiguttulate

Containing many oil droplets (guttules).^[304]

multilocular

See plurilocular.

A balloon-shaped ascus of Arthothelium spectabile containing eight hyaline, muriform ascospores.

muriform

Divided into compartments or locules by intersecting longitudinal and transverse septa.^[305] The term was first used by Wilhelm Körber in 1855.^[4]

muscicolous lichen

See bryophilous lichen.

-mycetes

A suffix indicating the taxonomic rank of a fungal class.^[306]

mycobiont

The fungal part of a lichen,^[307] which combines with one or more phycobionts.^[308] The term was proposed by George Scott in 1957.^[5]

mycophycobiosis

Main article: Mycophycobiosis

Also defined: mycophycobiont. A symbiosis where an ascomycete fungus is housed inside multicellular algae; the algae and fungus involved in this association are called mycophycobionts.^[309] Contrary to a lichen symbiosis, the fungal partner is the inhabitant, and the algal partner dominates.^[310]

myriotremoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Myriotremoid lichens have immersed apothecia with small pores, and a smooth and more or less shiny thallus; this morphotype occurs in the glaucopallens group of genus Myriotrema.^[30]

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N

necral layer

A layer of dead hyphae with indistinct lumina found near or in the cortex of a thallus.^[172] The term was first used by Alexander Elenkin in 1902.^[5] See related: epinecral layer, hyponecral layer.

nitid

Shiny, glossy, or polished in appearance; contrast with matte.^[252]

nodulose

Having small, rounded elevations or nodules.^[252]

nubilated

Cloudy or obscured, often used to describe the appearance of lichen apothecia that are partially covered.^[252]

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O

ob-

A prefix meaning "inversely" or "oppositely".^[311]

obclavate

Inversely clavate, widest at the base.^[311]

obovate

Egg-shaped, with the narrower end at the base.^[311]

obpyriform

Shaped like an inverted pear.^[312] See related: pyriform.

ocellularioid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Ocellularioid lichens have prominent apothecia with wide pores; pores with a "finger" (columella); black walls (viewed in microscopic section); and a smooth, more or less shiny thallus. This morphotype occurs in the genus Ocellularia.^[30]

-oid

A suffix meaning "like" or "having the form of".^[313]

The omphalodiscs of Umbilicaria phaea

omphalodisc

An apothecial disk with a bump in the center that gives it the appearance of a navel; found in the genus Umbilicaria.^[314] The term was introduced by George Llano in 1950.^[5]

orcularioid

A brown, polarilocular spore, characteristic of Rinodina section Orcularia.^[252]

ornithocoprophilic

Used to describe lichens that grow or proliferate in environments rich in bird excrement.^[267]

ostiole

Main article: Ostiole

A small pore or opening; in lichens, it is used to refer to the paraphysis-lined cavity in a parathecium that ends in a pore, or more generally to any pore from which spores are released from an ascus-bearing fruit body.^[315]

ostropalean

Referring to asci that are unitunicate with a thickened apex and a narrow canal ending in a pore; associated with species in the order Ostropales.^[316]

ovate

Egg-shaped, with the wider end at the base.^[317]

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P

pachydermatous

Also pachyderm, pachydermate, pachydermous. Referring to hyphae that have an outer wall that is thicker than the internal cavity.^[318]

palisade cell

A terminal cell of a hypha in a fastigiate cortex, aligned perpendicularly to the plane of the thallus.^[318]

palisade plectenchyma

Plural palisade plectenchymata. Also palisadoplectenchyma, plural palisadoplectenchymata. A type of plectenchyma in a cortex where the hyphae are arranged perpendicularly to the plane of the thallus.^[319]

pallidostegoboloid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Pallidostegoboloid lichens have prominent apothecia with wide pores; pore filled with irregular structures; pale walls (viewed in microscopic section); and a smooth, more or less shiny thallus. This morphotype occurs in wrightii group of the genus Stegobolus.^[30]

The thallus of Pycnothelia papillaria is covered with papillae.

papilla

Plural papillae. A small, conically rounded growth.^[320]

papillate

Also papillose. Covered with papillae.^[320]

papilliform

Having the shape of a papilla or nipple.^[321]

para-

Also par-. A prefix with several meanings, including "above", "beyond", "at the side", "against", "toward", and "almost".^[322]

paracephalodium

Plural paracephalodia. A mat of hyphae covering cyanobacteria, originating from a squamulose lichen with a green algal photobiont.^[323] The term was introduced by Josef Poelt and Helmut Mayrhofer in 1988.^[113]

paraphysoid

A threadlike, sterile, hyphal structure similar to a paraphysis, but typically branched and often forming a network.^[324]

paraplectenchyma

Plural paraplectenchymata. A type of plectenchyma comprising hyphae that are oriented in all directions; found in the cortex of many lichens.^[325]

parasoredium

A propagule, similar to a soredium, that starts as a budlike structure with hyphae on an upper side and algae on a lower side, then develops into blastidia. Originally used to describe a structure found on the upper thallus of Umbilicaria hirsuta.^[326]

parasymbiont

An organism that lives in close association with a host species, deriving benefits at the host's expense but not causing immediate harm; an intermediate state between symbiosis and parasitism.^[267]

parathecium

Plural parathecia. The outside layer of hyphae in an apothecium, curved upward along the margin of the hymenium;^[326] the term is now obsolete, and equivalent to ectal excipulum or proper exciple.^[327] Otto Darbishire coined the term parathecium in an 1898 monograph on the genus Roccella.^[5]

parmelioid lichen

An informal growth form category used for lichens that are mostly foliose, often closely attached to the substrate, and have laminal apothecia and pycnidia; this group of features is characteristic of lichens previously classified in the genus Parmelia (in the broad sense).^[93]

PD test

Also P test. A spot test that uses a 1–5% ethanolic solution of p-phenylenediamine as a reagent to check for the presence of certain lichen products.^[266]

pedicel

A small stalk used to support other structures, such as spores, asci, etc.^[328]

pedicellate

Having a pedicel.^[329]

peltate

Also clypeate, scutiform. Referring to a rounded structure attached on the lower side at a single central point (often on a short stalk), with free edges.^[330]

peltidiangium

A basket-like structure in which peltidia are produced.^[331]

peltidium

A reproductive propagule found in the foliicolous lichen genus Gallaicolichen that is similar in form to a goniocystangium, but is unique in that the photobiont partner organizes the propagule and envelops (or nearly so) its mycobiont partner. The term is derived from the name of the involved green algal genus, Phycopeltis.^[331]

pendant

Also pendent, pendulous. Hanging down, as in the fruticose thalli of genus Usnea, the beard lichens.^[332]

A perforate thallus is a character of the hypogymnioid genus Menegazzia (M. pertransita shown)

perforate

With splits or holes in the thallus.^[333]

periclinal

Parallel to a surface;^[334] used to refer to hyphal alignment.

perifulcrum

The protective wall surrounding a pycnidium.^[252]

periphysis

Plural periphyses. A short, sterile hypha that develops from above the ascus and grows down a short distance, typically lining the internal walls of the ostiole in a perithecium.^[335]

periphysoid

Periphysis-like structures that grow laterally; found in some crustose pyrenolichens.^[335]

perispore

Also defined: exospore, epispore, mesospore, endospore. The colorless and usually gelatinous outermost layer of a spore.^[336] This transparent layer determines the spore's shape.^[337] The other four layers of a spore, going inward, are the exospore, epispore, mesospore, and endospore.^[336]

Schematic illustration of a perithecium with an apical ostiole

perithecium

Plural perithecia. A spherical or flask-shaped ascocarp that is sessile or partly immersed in the thallus, with a single opening (ostiole) and enclosed by a distinct wall; a characteristic of pyrenolichens.^[338] Although it was in 1831 that Elias Fries first applied the term perithecium to lichen fruit bodies, the word was originally coined by Christiaan Hendrik Persoon in 1794.^[339]

petricolous

See epilithic.

phaeolichen

A lichen in which the photobiont partner is brown algae (class Phaeophyceae); an example is lichen formed by the fungus Wahlenbergiella tavaresiae and the brown alga Petroderma maculiforme.^[340]

phenocortex

Plural phenocortices, phenocortexes. A structure, similar to a cortex, containing hyphal fragments and dead, collapsed algal cells sloughed off from the algal layer.^[341]

photobiont

Also defined: phycobiont, cyanobiont. The photosynthetic component of a lichen. This can be either a green alga (known as a phycobiont) or a cyanobacteria (known as a cyanobiont).^[342] The term "phycobiont" was proposed by George Scott in 1957.^[5]

photobiont layer

See algal layer.

photomorph

An organism whose morphology is determined by the nature of its photosynthesis; applied to lichen-forming fungi whose thalli have different forms with green algal versus cyanobacterial photobionts.^[343] The term was introduced by Jack Laundon in 1995 to address what he believed were deficiencies in related terms such as morph, morphotype, and photosymbiodeme.^[344]

photosymbiodeme

Morphologically different structures formed by the interaction of a single mycobiont with two different photobionts. Examples occur in the genera Pseudocyphellaria and Sticta.^[345]

phycobiont

See: photobiont

phyllidium

Plural phyllidia. A small leaf-like or scale-like propagule that is corticate and has distinct upper and lower sides (i.e., it is dorsiventral); it originates from the margins or on the upper surface of thallus.^[346] Phyllidia occur in some species of the Lecanorales and the Peltigerales.^[347]

A closeup of Stereocaulon paschale shows that its phyllocladia have a granular or dactyliform shape, and are gathered in clusters along branches of the pseudopodetia.

phyllocladium

Plural phyllocladia. A photobiont-containing, corticate outgrowth of pseudopodetia; common in the genus Stereocaulon. Their morphology can be characterised with various descriptors: coralloid, digitate, granular, peltate, foliose, squamulose, and verrucose.^[347][348] The term was introduced by Theodor Fries in 1858.^[5]

phyllopsoroid

A lichen growth form characterized by mostly squamulose thalli with areoles or squamules often overgrowing a thick prothallus; this morphology occurs in the largely tropical genera Bacidiopsora, Eschatogonia, Phyllopsora, and Physcidia.^[349]

piriform

See pyriform.

placodioid lichen

Also placoid, placodiomorph. A crustose lichen with an areolate center and radiating lobes on the circumference.^[350]

plasticolous lichen

Main article: Plasticolous lichen

A lichen that grows on plastic.^[351]

platycarpoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus structure. Similar to chroodiscoid or leprocarpoid, but the difference lies in the presence of a free excipulum that forms a distinct double margin. It is exemplified in species such as Chapsa platycarpa and C. neei.^[352]

platygonidium

Plural platygonidia. Photobionts that occur in star-shaped or circular colonies; now obsolete.^[353]

plectenchyma

Main article: Plectenchyma

Plural plectenchymata. Fungal tissue made of twisted, intertwined hyphae; used as a general term to refer to all types of fungal tissue.^[354] The term (and the use of the prefixes "para-" and "proso-" to modify it) was proposed by Gustav Lindau in 1899.^[5] See related: paraplectenchyma, prosenchyma, prosoplectenchyma, pseudoparenchyma.

plicate

Characterised by longitudinal folds forming pleats, often used to describe closely adjacent, markedly convex thallus lobes or elongated areoles that display a "folded" appearance.^[355]

plurilocular

Also multilocular. Having many cavities or locules; used to describe spore structure.^[356]

podetium

Main article: Podetium

Plural podetia. An upright, hollow, stem-like structure bearing apothecia and sometime conidiomata; typically associated with the Cladoniaceae, particularly the genus Cladonia.^[356] The term was first used by Erik Acharius in 1803.^[3]

POL test

A lichen test performed by shining a polarized light at a lichen structure in microscopic view; in the genus Hypogymnia, the presence (POL+) or absence (POL−) of POL-sensitive crystals in the hypothecium is a useful character to help distinguish species.^[357]

polarilocular

Also placodiomorphic,^[252] polar-diblastic, polaribilocular, polocellate. A spore divided into two components (locules) separated by a central septum with a perforation or isthmus.^[358][359] The term was first used by Wilhelm Körber in 1855 (as "polari-dyblastae") to describe the spores of Rhizocarpon and Umbilicaria. It was anglicized to "polari-bilocular" by William Mudd in 1861, and finally shortened to polarilocular by the Henri Olivier in 1882.^[4]

Polychroa-brown

An orange-brown to ochre insoluble lichen pigment, associated with the reference species Bacidia polychroa.^[56]

poriform

Shaped like or resembling a pore.^[360]

porinoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus structure. This morphotype is similar to ocellularioid, but with a very narrow pore that resembles the opening of a true perithecium. Despite this, the hymenium remains organized in a distinct, compact layer with paraphyses and asci of similar height. Examples include Leucodecton bisporum, L. compunctellum, and T. patwardhanii.^[361]

praestantoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Praestantoid lichens have large and prominent apothecia with small pores; pores with "finger" (columella); black walls (viewed in microscopic section); and a smooth, more or less shiny thallus. This morphotype occurs in the praestans group of the genus Ocellularia.^[30]

primary species

The sexually fertile member of a species pair.^[362]

primary thallus

See cladoniiform lichen.

prominent

Sticking out from the surface of the thallus.^[363] A more precise definition has been suggested by Aptroot and Lücking, who propose that the term applies to ascomata and pseudostromata that are more than 1/2 above the level of the thallus, and have a base that is expanded outwards.^[179]

proper margin

Also proper exciple, ectal excipulum, medullary excipulum, proprium. A ring of tissue around the disk of a lecanorine apothecium; this tissue, which originates from the medulla, is not lichenized, and is internal to the thalline margin (if present).^[364] The term "proper margin" was first used by Erik Acharius in 1803; in 1825 Elias Fries changed the noun and called it "proper exciple".^[3]

proprium

See proper exciple.

prosenchyma

Plural prosenchymata. A type of plectenchyma in which the constituent fungal hyphae are arranged parallel to each other, such that individual hyphae can be clearly distinguished using microscopy.^[365]

prosoplectenchyma

Plural prosoplectenchymata. A type of plectenchyma, common in the thallus cortex of lichens, in which the constituent fungal hyphae are aligned in a particular direction.^[365]

A fibrous white prothallus bordering the thallus is evident in this crustose Coenogonium.

prothallus

Main article: Prothallus § In lichens

A fungal layer upon which an algae-containing thallus may develop, lacking photobiont; usually white, brown, or black, and found between the areoles and at the growing margins of crustose lichens.^[366] The term was first used by Georg Meyer in 1825.^[3]

prototunicate

A form of unitunicate ascus in which the wall breaks down before maturity (thus releasing its ascospores), and which lacks differentiated apical structures.^[367]

proximal

Positioned close to a point of origin or near the center of a body.^[368]

pruina

A powdery, frost-like or flour-like deposit on a surface. In lichens, pruina is often the result of the accumulation of crystalline hydrates of calcium oxalate, of lichen products, or sometimes of the dead or dying cells of the epinecral layer.^[369]

pruinose

Also pruinate. Covered with pruina.^[368]

pseudo-

Also pseud-. A prefix meaning "false";^[370] used in terminology to denote something is false, or that one structure resembles something else, such as the pseudocyphella resembling the cyphella.^[368]

pseudoamyloid

See dextrinoid.

pseudocortex

Plural pseudocortices, pseudocortexes. A boundary layer of the thallus containing distinct hyphae that are not organized into a regular tissue structure;^[371] sometimes used to refer to the false cortex present on the outer layer of pseudopodetia, such as those found in the lichen Pycnothelia papillaria.^[372]

Both white pseudocyphellae and larger, coarse soredia are apparent on the thallus of this Punctelia caseana.

pseudocyphella

Main article: Pseudocyphella

Plural pseudocyphellae. Small openings in the cortex of a lichen, where the medulla is exposed to air, and there are no specialized cells surrounding the cavity.^[373] The term was first used by William Nylander in 1858.^[4]

pseudoisidium

Plural pseudoisidia. An outgrowth on the surface of a lichen thallus that somewhat resembles an isidium, but lacks photosynthetic cells; pseudoisidia are common in the genus Pseudocyphellaria.^[374]

pseudoparaphysis

Also cataphysis. A paraphysis-like hypha that forms in the locule or perithecial cavity before the formation of the ascus; it grows downward from the top of the cavity to the base of the ascomata.^[375]

pseudoparenchyma

Plural pseudoparenchymata. A type of plectenchyma made of tightly packed, angular or polyhedral cells.^[375]

Pilophorus acicularis features rounded black apothecia at the end of pseudopodetia.

pseudopodetium

Plural pseudopodetia. Solid, upright stalks originating from the thallus. They are similar to podetia, but are made of vegetative (rather than generative) tissue.^[376] They are associated with the genera Baeomyces, Dibaeis, Leprocaulon, Pilophorus, and Stereocaulon.^[377] The term was introduced by Gustav Krabbe in 1882.^[5]

pseudostroma

Plural pseudostromata. A stroma made of both thallus tissue and bits of host tissue.^[378] The term was used first for lichenized fungi Edvard August Vainio in 1890.^[5]

pubescent

Covered with short, soft, fine hairs or down.^[360]

pulverulent

Characterised by a fine, powdery surface or consistency; resembling or appearing as dust or powder.^[379]

punctate

Having a pattern of minute spots or tiny holes (also known as puncta).^[380]

punctiform

Very small or tiny, appearing as a point or dot.^[381]

pustulate

Also pustulose. Covered with pustules.^[382]

pustule

A blister- or wart-like structure, usually hollow.^[383]

pycnidium

Plural pycnidia. An asexual fruiting body, or conidium, that is typically round, obpyriform, or lageniform. It has a circular or elongated ostiole that has an inner surface lined with conidiophores. Pycnidia are common in anamorphic fungi, including many lichenicolous species.^{[384] [385]}

pycnoascocarp

A type of apothecium that originates from a pycnidium; characteristic of the family Lichinaceae.^[384] The term was first used by Aino Henssen in 1963.^[5]

pyrenocarpous lichen

A lichen with flask-shaped fruiting bodies (perithecia) that develop from the fungal partner. Originally thought to form a natural group, molecular studies have shown pyrenocarpous lichens to be highly polyphyletic, evolving independently in multiple fungal lineages. Most belong to Chaetothyriomycetidae (e.g., Verrucariales, Pyrenulales), with some in Dothideomycetes (e.g., Arthopyreniaceae, Trypetheliaceae) and others unusually placed in Lecanoromycetes (e.g., Porinaceae, Protothelenellaceae, Thelenellaceae). Pyrenocarpous lichens are notably absent from the classical pyrenomycete class Sordariomycetes. This diverse group demonstrates that ascoma morphology alone is insufficient for determining evolutionary relationships, with convergent evolution of perithecial fruiting bodies occurring multiple times across fungal lineages.^[386]

pyrenolichen

A lichen that produces perithecia.^[387]

pyriform

Also piriform. Shaped like a pear.^[388] See related: obpyriform.

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R

radial

Also radiate.^[389] Referring to lichen thalli, symmetrical around a central axis in transverse section, such as in the genera Alectoria, Bryoria, and Usnea.^[390]

radiate

Spreading from a central point.^[390]

recurved

Also recurvate, reflexed.^[391] Curved or bent back; in lichens, these terms are used to describe the tips of branches or lobes that are curved up or down, or back onto themselves.^[392]

redingerioid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Redingerioid lichens have immersed apothecia with linear slit; slit filled with irregular structures; black walls (viewed in microscopic section); and a smooth, more or less shiny thallus. This morphotype occurs in the genera Redingeria and Stegobolus.^[30]

reimnitzioid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Reimnitzioid lichens have open apothecia with erect lobules, and a rough thallus containing crystals; this morphotype occurs in the genus Reimnitzia.^[30]

reniform

Shaped like a kidney.^[360]

reticulate

Marked like a net or network.^[393]

Black, fibrous, and tufted rhizines are on the thallus underside of Peltigera neopolydactyla.

rhizine

Main article: Rhizine

Also rhizina, plural rhizinae. A root-like structure that serves as an attachment structure in many foliose lichens.^[394][395]

rhizinomorph

A root-like structure similar to a rhizine that is not involved as an attachment organ; associated with umbilicate lichens.^[396]

rhizinose strand

An attachment organ, similar to a rhizine, comprising tough and irregularly branched hyphae; found in some squamulose lichens, such as in the genera Catolechia and Toninia.^[397][395]

rhizohypha

A single hyphal strand on the thallus underside that serves as an attachment organ.^[396]

rhodostromoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Rhodostromoid lichens have large and prominent apothecia with small pores; pore with “finger” (columella); black walls and pigment (viewed in microscopic section); and a smooth, more or less shiny thallus. This morphotype occurs in the rhodostroma group of the genus Ocellularia.^[30]

rimose

Also rimous. Having cracks or splits.^[398]

rimula

Plural rimulae. Small, rim-like structures or cracks.^[399]

rimulose

Also rimulous. Having minute cracks or splits.^[399]

rivose

Marked with curvy and irregular furrows, like the thallus of some crustose lichens.

rivulose

Marked with thin, winding or crooked lines.^[400]

rostrate

Having a rostrum.^[401]

rostrum

Plural rostra. A beak-like projection.^[402]

Ruginosa-brown

A dark red to almost black insoluble lichen pigment, associated with the reference species Toninia ruginosa.^[403]

rugose

Also rugous. Having a rough texture; wrinkled and creased.^[404]

rugulose

Also rugulate. Having a slightly rough texture; with slight wrinkles and creases.^[404]

rupicolous

See saxicolous.

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S

saccate

Sac- or bag-like in form.^[405]

saxicolous lichen

Main article: Saxicolous lichen

A lichen that grows on stone.^[73]

scabioid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus structure. This morphotype resembles the leprocarpoid but features recurring hymenia that produce layered excipula, which eventually cover the disk; examples include Chapsa aggregata and C. albomaculata.^[406]

scabrous

Also scabrose, scabrid, scabridous. With a crusty, rough surface often resulting from the accumulation of dead cortical material.^[407][383]

schizidium

Plural schizidia. A scale-like propagule originating from the upper layers of a lichen thallus.^[408] The term was proposed by Josef Poelt in 1965.^[5]

schizobiont

A bacterium that lives in or is associated with a lichen thallus.^[409]

schizotremoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Schizotremoid lichens lack apothecia and have schizidia, and a smooth, more or less shiny thallus; this morphotype occurs in the genus Stegobolus.^[30]

Schweinitzii-red

A dark red insoluble lichen pigment, associated with the reference species Bacidia schweinitzii.^[42]

scleroplectenchyma

Plural scleroplectenchymata. A type of plectenchyma comprising thick-walled hyphae that are stuck closely together; present as a component of the stereoma tissue supporting the thallus in the genera Cladonia and Alectoria.^[408]

scrobiculate

Having large, shallow depressions that are narrowly separated by rounded ridges.^[191] Compare: faveolate, foveolate.

Cup-shaped scyphi atop the podetia of Cladonia fimbriata

scyphus

Plural scyphi. The cup-shaped part at the tip of a lichenized podetium, common in the genus Cladonia.^[410] The term was first used by Johann Dillenius in 1742, and later adopted by Carl Linnaeus in 1753.^[4]

scutiform

See peltate.

secondary species

The sexually infertile member of a species pair that only reproduces vegetatively.^[362]

secondary thallus

See cladoniiform lichen.

Sedifolia-gray

A blackish-gray to gray-green insoluble lichen pigment, associated with the reference species Toninia sedifolia.^[57]

segment

A section of a branch that is demarcated by an annular (ring-like) crack.^[411]

septum

Main article: Septum

A wall or partition in a hypha, cell, or spore.^[412]

seriate

Arranged in rows.^[413]

sessile

Main article: Sessility (botany)

Lacking a stem.^[414] A more precise definition has been suggested by Aptroot and Lücking, who propose that the term applies to ascomata and pseudostromata that are more than 3/4 above the level of the thallus, with a constricted base.^[179]

sibling species

Closely related species that are morphologically indistinguishable but can be distinguished by non-morphological traits, such as chemistry or genetic differences. Initially defined as species recognized mainly through cryptic or non-morphological discontinuities, the concept has evolved to specifically refer to cryptic species that form a monophyletic group, meaning they share a common ancestor not shared with any other species. This concept is a subset of the broader terms species pair and "cryptic species".^[415]

sigmoid

Curved upon itself twice, like the letter "S".^[416]

simple

Lacking branches or divisions; in lichenology, it is used to describe structures such as thalli or rhizines, or spores without septa.^[417]

siphuloid

An informal growth form category applied to lichen genera with a superficially similar foliose to fruticose morphology, notably Siphula, Siphulella, Siphulopsis, Parasiphula, and Knightiellastrum.^[418]

soleiform

Shaped like the sole of a shoe, with a flat, elongated, and slightly curved appearance.^[419]

An accumulation of granular soredia is evident on the inner lobe margin soralia of this Flavoparmelia caperata.

soralium

Plural soralia. A part of the thallus where the cortex has cracked or broken down and soredia are produced. Soralia can be further characterized as diffuse if they are spread out on the upper thallus surface as a continuous layer, or delimited if they are confined to a more restricted area. If soralia originate in tubercules they are tuberculate, while they are fissural if they are created in fissures.^[420] The term was proposed by Johannes Reinke in 1895.^[5]

sorediate

Having soredia.^[420]

sorediotremoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Sorediotremoid lichens lack apothecia and have soralia, and a smooth, more or less shiny thallus; this morphotype occurs in the genera Myriotrema and Ocellularia.^[30]

soredium

Plural soredia. A powdery to granular reproductive propagule that is not covered with a well-defined cortex (in contrast to isidia, and contains both algal (photobiont) and fungal (mycobiont) components.^[420] The term was first used by Erik Acharius in 1803.^[3]

spathulate

Spoon-shaped.^[421]

species pair

Two lichen species that are identical morphologically, anatomically, and chemically, but can be distinguished by their sexual versus asexual reproductive strategies; the fertile taxon is known as the primary species, while the vegetatively reproducing taxon is known as the secondary species.^[362] The use of molecular methods to analyze putative species pairs has shown that the underlying phylogenetic situation is more complex than had been assumed, and not necessarily correlated with reproductive strategy.^[422] See related: sibling species.

spermogonium

Also spermagone, spermagonium. In lichenology, an obsolete term for pycnidium.^[423]

sphaeridium

Plural sphaeridia; see capitulum.

spinule

A small spine; in some fruticose lichens of the Lecanoromycetes, it refers to a small cylindrical outgrowth, with a narrow base, in which the central axis is not connected with the central axis of the main branch.^[424]

spinulose

Also spinulous. Covered with or having small spines (spinules) or spiny projections.^[424]

Closeup of the spongiostratum on the lobe undersides of Anzia colpodes

spongiostratum

Plural spongiostrata. A spongy hypothallus found on the lower thallus surface of the genera Anzia and Pannoparmelia.^[425][426]

sporodochium

Plural sporodochia. A cushion-shaped stroma consisting of short conidiophores and pseudoparenchyma that supports a spore mass.^[427]

sporomorph

A lichen species that is extremely similar (or identical) in external morphology, anatomy, chemistry, and spore size to another, but that is placed in a different genus solely based on differences in spore septation and/or spore colour. The term was introduced by Michael Wirth and Mason Hale in their 1978 monograph about the Graphidaceae, a family in which sporomorphs are common.^[428]

In this spot test, a red color resulting from the application of C on Dirina massiliensis f. sorediata indicates the presence of erythrin.^[429]

spot test

Main article: Spot test (lichen)

A spot analysis used to help identify lichens; it is performed by placing a drop of a reagent on different parts of the lichen and noting any color change associated with application of the reagent. The four most common tests are C, K, KC, and PD.^[430]

squamulose lichen

Main article: Squamulose lichen

A lichen with a thallus made of numerous small scales or lobes; intermediate in form between crustose and foliose lichens.^[431]

squarrose

Brush-like, with many short, more or less perpendicular lateral branches. In lichenology, used to refer to rhizine structure.^[432]

stegoboloid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Stegoboloid lichens have prominent apothecia with wide pores; pore filled with irregular structures; black walls (viewed in microscopic section); and a smooth, more or less shiny thallus. This morphotype occurs in the genus Stegobolus.^[30]

stereoma

Plural stereomata. Tissue that provides support for the thallus in some species of Lecanorales.^[431] See related: scleroplectenchyma.

stratified thallus

A thallus that is divided into distinct layers (strata).^[433] See related: heteromerous.

stroma

Main article: Stroma (tissue)

Plural stromata. A dense mass of vegetative hyphae that supports spore-bearing structures.^[434] In lichens, the stroma is often hard and carbonaceous.^[396]

sub-

A prefix meaning "below", "under", "somewhat, or "almost".^[435] Also used in front of names of taxonomic ranks to indicate intermediate categories, e.g. subspecies or subgenus.^[436]

subhymenium

The tissue immediately below the hymenium.^[435] The term was first used by Gustaf Einar Du Rietz in 1945.^[5]

subiculum

Also subicule. Plural subicula. A layer of loosely-compacted mycelia that covers the substrate and cushions fruiting bodies such as apothecia and perithecia.^[437] The texture of the subiculum can be described as net-like, wool-like, or crust-like.^[435]

substrate

Main article: Substrate (biology)

Also substratum; plural substrata. The surface or base upon which a lichen grows or is attached. Although the terms substratum and substrate are often used equivalently in lichenology, the latter term has different meanings in microbiology and in enzymology.^[438]

subulate

Slender and narrowing to a fine point; awl-shaped.^[439]

sulcate

With grooves or furrows.^[439]

Superba-brown

An orange-brown to ochre insoluble lichen pigment, associated with the reference species Porpidia superba.^[60]

superficial

On the surface.^[439]

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T

The species name of Ochrolechia tartarea refers to its coarse and fragmented surface.

tartareous

Also tartarean. Having a thick, rough, and crumbly surface.^[440]

taxon

Main article: Taxon

Plural taxa. A taxonomic group of any rank; this includes species, genera, families, etc., up to kingdom and even higher.^[440]

tenuitremoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus morphology. Tenuitremoid lichens have immersed apothecia with small pores and a black margin; pore with “finger” (columella); black walls (viewed in microscopic section); and a smooth, more or less shiny thallus. This morphotype occurs in the genus Clandestinotrema.^[30]

tegulicolous lichen

A lichen that lives on tiles.^[441] In general, these are calcicolous lichens or lichens that are indifferent as to their substrate.^[442]

terebrate

A thallus with widely spaced perforations.^[443]

terete

Describing a cylindrical or rod-like structure that is round in cross-section.^[419]

teretiform

Describing a shape that is nearly cylindrical or rod-like, similar to but not exactly terete; circular in cross-section, gradually tapering towards one end.^[444]

terricolous lichen

Main article: Terricolous lichen

A lichen that grows on soil.^[73]

The tessellated thallus of the map lichen, Rhizocarpon geographicum

tessellate

Main article: Tessellation

As if formed of small squares or mosaics, like the thallus of Rhizocarpon geographicum.^[445]

thalline margin

Also thalline exciple, excipulum thallinum. A rim of tissue around the disk of a lecanorine apothecium; this tissue, external to the inner proper margin, is made of tissue with a structure similar to that of the thallus.^[446] The term "thalline margin" was first used by Erik Acharius in 1803; in 1825 Elias Fries changed the noun and called it "thalline exciple".^[3]

thallinocarp

A type of ascocarp characteristic of the genus Lichinella (family Lichinaceae); they form from indistinct swellings of the thallus, with a hymenium covered by groups of algal cells.^[447]

thalloconidium

Plural thalloconidia. A dark brown, smooth to wrinkled propagule arising directly from a thallus, particularly the lower cortex and/or the rhizines. They are found in some species of Umbilicaria, and similar structures arise from the prothallus of some species in the genera Protoparmelia, Rhizoplaca, and Sporastatia. Thalloconidia have distinct cell layers in their walls, and comprise between 1 and about 2500 cells.^[448][449]

thalloid

Similar to a thallus.^[448]

thallospore

An asexual spore produced directly in the thallus or in mycelium.^[448] In lichens, they are primarily associated with the genus Umbilicaria, although they also occur in some crustose lichens.^[450]

thallus

Main article: Thallus

Plural thalli. The body of a lichen,^[451] made up of both fungal and algal or cyanobacterial cells.^[452] The term was first used by Erik Acharius in 1803.^[3]

thallyle

A small thallus that originates from rhizomorphs; typically associated with the genus Umbilicaria.^[419]

thecium

Plural thecia. The part of an apothecium that contains the asci and is situated between the epithecium and the hypothecium.^[453] The term is alternatively used more generally to refer to any fruit body that is delimited by a proper wall (i.e., containing only fungal cells), or, as equivalent to hymenium.^[448] This last usage was first employed by William Nylander in 1853.^[4] See related: apothecium, amphithecium, hamathecium, parathecium, perithecium.

Thelotrema lepadinum is a thelotremoid lichen.

thelotremoid

A morphological group of lichens within the Graphidaceae, the largest family of crustose lichens.^[454] Thelotremoid lichens are characterized by immersed-erumpent, rounded ascomata, non-branched to slightly branched paraphyses, mostly distoseptate ascospores, and mostly a prosoplectenchymatous excipulum. Thelotremataceae, a traditional family of lichens, has been included in Graphidaceae, and its species are now informally accepted as thelotremoid lichens.^[454]

tholus

Plural tholi. Also dome. The apical, often thickened part of the inner wall in a bitunicate ascus.^[455]

tomentum

Plural tomenta. Also defined: tomentose. A layer of short interwoven or coiled fungal hyphae with a texture similar to velvet. In lichens, the tomentum projects from the lower cortex and serves to help it attach to its substrate. Structures with this type of hyphae are called tomentose.^[456] Tomentose surfaces are found in foliose genera such as Lobaria, Pseudocyphellaria, and Sticta.^[457]

topeliopsidoid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus structure. It pertains to lichens where the apothecia are either prominent or sessile, often hidden between the substratum, and they open with multiple, typically regular "teeth" that stay relatively curved over the hardly visible disk. The margins tend to peel off, meaning the overlaying thallus cortex separates from the underlying marginal thallus tissue, but no distinct, clean split between thallus margin and excipulum is formed. This morphotype is seen in species like Chapsa meridensis and Topeliopsis.^[458]

trabecula

Plural trabeculae. In the genus Umbilicaria, they are rib- or strap-shaped structures radiating outward from the umbilicus that merge towards the mid-zone of the thallus undersurface.^[271]

trentepohlioid

Resembling or belonging to the green algal genus Trentepohlia; trentepohlioid cells are filamentous (elongated and cylindrical), multicellular, and have a yellow to orange colour.^[459]

trebouxioid

Resembling or belonging to the green algal genus Trebouxia; trebouxioid cells are globose with a single central chloroplast.^[460]

triguttulate

Containing three oil droplets (guttules).^[228]

tripartite lichen

A lichen with a three-partner symbiotic association of mycobiont, photobiont, and cyanobiont.^[64] See related: bipartite lichen.

tuberculate

Also tubercular. Covered with tubercules.^[461]

tubercule

Also tubercle. A small rounded wart-like projection on a surface.^[461]

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U

Umbilicaria phaea is a saxicolous, umbilicate lichen.

umbilicate lichen

Also defined: funiculus, umbilicus, umbilical cord. A lichen with a concave, circular, leafy thallus that is joined to its substrate only by its central part, called an umbilicus, umbilical cord or funiculus.^[462][463]

unciform

Hook-shaped.^[464]

undulate

Having a wavy form, margin, or surface.^[465]

uni-

A prefix meaning "one"; equivalent to the prefix "mono-".^[466]

uniguttulate

Containing a single oil droplet (guttule).^[466]

unilocular

Containing a single cavity or locule.^[466]

uniseriate

Lined up in a single row.^[467]

unitunicate

A type of ascus with a single functional layer; the rigid internal and external wall layers do not separate during release of the ascospores. Most ascomycetes have unitunicate asci.^[467]

urceolarioid

A morphotype of corticolous thelotremoid lichens used to describe characteristics of apothecial and thallus structure. In this, the fruiting bodies are noticeable to sessile and have a narrow pore with a smooth margin, through which the disk and excipulum are not visible. This morphotype can be observed in Thelotrema isidiophorum, T. subweberi, and T. weberi.^[468]

Closeup of the urceolate apothecia of Stictis urceolata

urceolate

Deeply cup-shaped or urn-shaped; in lichens, the term is used to describe some apothecia with a sunken hymenium and elevated parathecium that forms a narrow mouth.^[469]

usneoid lichen

An informal growth form category used for fruticose lichens with an elastic central axis in the medulla; these features are characteristic of lichens in the genera Dolichousnea and Usnea.^[470]

UV test

A lichen test performed by shining a long-wavelength ultraviolet light (350 nm) at a lichen structure to check if it fluoresces; a positive test (abbreviated as UV+) indicates the presence of certain lichen products. Xanthone compounds in the cortex tend to fluoresce yellow, orange, or red, while depsides and depsidones in the medulla fluoresce blue to white.^[471]

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V

Veins on the underside of Peltigera membranacea

vagrant

Main article: Vagrant lichen

A lichen not attached to a substrate, typically able to be blown around by wind.^[472]

vegetative

Also assimilative. Having to do with the growth phase of an organism before reproduction, including spore germination, growth, development and asexual multiplication.^[473]

vegetative reproduction

Main article: Vegetative reproduction

Also vegetative multiplication. Any form of asexual reproduction;^[473] in lichens, this can involve just the mycobiont (as with thalloconidia), or both the mycobiont and photobiont, as with blastidia, isidia, and soredia.

vein

A cord of tissue on the underside of a foliose thallus, common in the genus Peltigera.^[474]

verruca

Plural verrucae. A small, cone-shaped protuberance, like a small wart.^[475]

Verrucarioides-brown

A dull brown insoluble lichen pigment, associated with the reference species Toninia verrucarioides.^[60]

verruciform

Having a wart-like shape.^[476]

verrucose

A rough surface covered with verrucae.^[475]

verruculose

A surface covered with tiny verrucae; delicately verrucose.^[477]

vitricolous lichen

A lichen that grows on glass.^[478]

voucher

A museum specimen that corresponds to a field collection.^[479]

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X

xantho-

Also xanth-. A prefix used to indicate the color yellow.^[480]

The saxicolous, crustose species Verrucaria funckii is a xantholichen.

xantholichen

A lichen in which the photobiont partner is yellow-green algae (class Xanthophyceae); an example is the lichen formed by the fungus Verrucaria funckii and the yellow-green alga Heterococcus caespitosus.^[340]

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Z

zeorine

An apothecium with both a thalline exciple and a proper exciple. The term refers to apothecia characteristic of Zeora,^[481] a defunct genus that is now synonymous with Lecanora;^[482] consequently, the term is more or less obsolete and is equivalent to lecanorine.^[483]

zonate

Having concentric lines that form alternating light and dark zones near the thallus margin of a crustose lichen.^[484]

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See also

Main article: Outline of lichens

• Glossary of biology
• Glossary of mycology
• Glossary of scientific naming
• List of common names of lichen genera
• List of Latin and Greek words commonly used in systematic names

Citations

1. "Introduction to Lichens". 2014-08-22. Archived from the original on 2014-08-22. Retrieved 2022-07-24.
2. "What is a lichen? - Lichen website". 2014-07-02. Archived from the original on 2014-07-02. Retrieved 2022-07-24.
3. Mitchell 2014, p. 13.
4. Mitchell 2014, p. 14.
5. Mitchell 2014, p. 15.
6. Kirk et al. 2008, p. 1.
7. Ulloa & Hanlin 2012, p. 3.
8. Cannon & Kirk 2007, p. 384.
9. Orange, James & White 2001, p. 6.
10. Ulloa & Hanlin 2012, p. 4.
11. Smith et al. 2009, p. 22.
12. Ulloa & Hanlin 2012, p. 6.
13. Ulloa & Hanlin 2012, p. 9.
14. Kirk et al. 2008, p. 7.
15. Ulloa & Hanlin 2012, p. 8.
16. Kirk et al. 2008, p. 9.
17. Ulloa & Hanlin 2012, p. 7.
18. Øvstedal & Lewis Smith 2001, p. 367.
19. Brodo, Sharnoff & Sharnoff 2001, p. 755.
20. Ulloa & Hanlin 2012, p. 16.
21. Thell et al. 2012, pp. 645, 655.
22. Brodo 2016, p. 369.
23. Cannon & Kirk 2007, p. 385.
24. Vondrák et al. 2023.
25. Kirk et al. 2008, p. 23.
26. Ulloa & Hanlin 2012, p. 20.
27. Kirk et al. 2008, p. 26.
28. Ryan et al. 2022, page: Amphithecium.
29. Mitchell 2014, pp. 14–15.
30. Mercado-Díaz et al. 2015, p. 16.
31. Ulloa & Hanlin 2012, p. 21.
32. Ulloa & Hanlin 2012, p. 22.
33. Ulloa & Hanlin 2012, p. 26.
34. Ryan et al. 2022, page: Anisotomic.
35. Kirk et al. 2008, p. 40.
36. Ulloa & Hanlin 2012, p. 30.
37. Kirk et al. 2008, p. 42.
38. Kirk et al. 2008, p. 44.
39. Kirk et al. 2008, p. 45.
40. Cannon & Kirk 2007, p. 387.
41. Ulloa & Hanlin 2012, p. 36.
42. Meyer & Printzen 2000, p. 582.
43. MacKenzie Lamb 1968, p. 85.
44. Ulloa & Hanlin 2012, p. 37.
45. Ulloa & Hanlin 2012, p. 38.
46. Meyer & Printzen 2000, p. 578.
47. Cannon & Kirk 2007, p. 388.
48. Ulloa & Hanlin 2012, p. 41.
49. Kirk et al. 2008, p. 54.
50. Honegger 1991, p. 555.
51. Ulloa & Hanlin 2012, p. 42.
52. Silverstein, Silverstein & Silverstein 1996, p. 32.
53. Cannon & Kirk 2007, p. 63.
54. Nelsen et al. 2014, p. 982.
55. Ulloa & Hanlin 2012, p. 48.
56. Meyer & Printzen 2000, p. 579.
57. Meyer & Printzen 2000, p. 581.
58. Rivas Plata et al. 2010, p. 141.
59. Ulloa & Hanlin 2012, pp. 54–55.
60. Meyer & Printzen 2000, p. 580.
61. Ulloa & Hanlin 2012, p. 60.
62. Cannon & Kirk 2007, p. 390.
63. Ulloa & Hanlin 2012, p. 61.
64. Nelsen et al. 2020, p. 21496.
65. Garrido-Benavent & Pérez-Ortega 2017.
66. Ryan et al. 2022, page: Biseriate.
67. Ulloa & Hanlin 2012, p. 68.
68. Brodo, Sharnoff & Sharnoff 2001, p. 756.
69. Poelt 1980.
70. Grube & Hawksworth 2007, p. 1117.
71. Randlane et al. 2009, p. 421.
72. Ryan et al. 2022, page: Branchlet.
73. British Lichen Society.
74. Lendemer, Buck & Harris 2016, p. 441.
75. Upreti & Rai 2013, p. 2.
76. Kirk et al. 2008, p. 106.
77. Ulloa & Hanlin 2012, p. 77.
78. Ahmadjian & Hale 1973, p. 635.
79. Ulloa & Hanlin 2012, p. 81.
80. Ulloa & Hanlin 2012, p. 82.
81. Øvstedal & Lewis Smith 2001, p. 368.
82. Kirk et al. 2008, p. 114.
83. Ulloa & Hanlin 2012, p. 84.
84. Ulloa & Hanlin 2012, p. 89.
85. Smith et al. 2009, p. 24.
86. Ulloa & Hanlin 2012, p. 92.
87. Breuss 2010.
88. Kirk et al. 2008, p. 121.
89. Kirk et al. 2008, p. 122.
90. Cannon & Kirk 2007, p. 392.
91. Ahmadjian & Hale 1973, p. 49.
92. Ulloa & Hanlin 2012, p. 98.
93. Thell et al. 2012, p. 645.
94. Weber & Büdel 2011, p. 348.
95. Ryan et al. 2022, page: Checklist.
96. Kirk et al. 2008, p. 135.
97. Ryan et al. 2022, page: Chlorococcoid.
98. Kirk et al. 2008, p. 143.
99. Meyer & Printzen 2000, pp. 580–581.
100. Ulloa & Hanlin 2012, p. 106.
101. Smith et al. 2009, p. 13.
102. Ahti 1982, p. 105.
103. Ulloa & Hanlin 2012, p. 107.
104. Kirk et al. 2008, p. 153.
105. Ryan et al. 2022, page: Coccoid.
106. Kirk et al. 2008, p. 162.
107. Kirk et al. 2008, p. 163.
108. Ulloa & Hanlin 2012, p. 122.
109. Brodo, Sharnoff & Sharnoff 2001, p. 757.
110. Ulloa & Hanlin 2012, p. 124.
111. Ulloa & Hanlin 2012, p. 121.
112. Büdel & Scheidegger 2008, p. 64.
113. Mitchell 2014, p. 16.
114. Kirk et al. 2008, p. 170.
115. Kirk et al. 2008, p. 172.
116. Kirk et al. 2008, p. 173.
117. Ulloa & Hanlin 2012, p. 133.
118. Kirk et al. 2008, p. 176.
119. Ulloa & Hanlin 2012, p. 134.
120. North American Mycological Association.
121. Brodo 2016, p. 371.
122. Hertel 2009, p. 185.
123. Hafellner & Kalb 1995, pp. 163–164.
124. Hafellner & Kalb 1995, p. 163.
125. Kirk et al. 2008, p. 1842.
126. Kirk et al. 2008, p. 184.
127. Kirk et al. 2008, p. 183.
128. Rikkinen 2015, p. 973.
129. Kirk et al. 2008, p. 187.
130. Ryan et al. 2022, page: Decorticate.
131. Kirk et al. 2008, p. 196.
132. Ulloa & Hanlin 2012, p. 151.
133. Ulloa & Hanlin 2012, p. 152.
134. Ulloa & Hanlin 2012, p. 153.
135. Ulloa & Hanlin 2012, p. 156.
136. Kirk et al. 2008, p. 201.
137. Ulloa & Hanlin 2012, p. 157.
138. Brodo 2016, p. 372.
139. Ferraro 2004, p. 154.
140. Ulloa & Hanlin 2012, p. 162.
141. Brodo, Sharnoff & Sharnoff 2001, p. 293.
142. Ulloa & Hanlin 2012, p. 163.
143. Ulloa & Hanlin 2012, p. 166.
144. Ulloa & Hanlin 2012, p. 167.
145. Kirk et al. 2008, p. 216.
146. Korf 1962, p. 25.
147. Kirk et al. 2008, p. 217.
148. Cannon & Kirk 2007, p. 399.
149. Ulloa & Hanlin 2012, p. 170.
150. Ulloa & Hanlin 2012, p. 175.
151. Ulloa & Hanlin 2012, p. 176.
152. Ulloa & Hanlin 2012, p. 177.
153. Kirk et al. 2008, p. 226.
154. Büdel & Scheidegger 2008, p. 42.
155. Kirk et al. 2008, p. 228.
156. Smith et al. 2009, p. 31.
157. Ulloa & Hanlin 2012, p. 182.
158. Ulloa & Hanlin 2012, p. 183.
159. Ulloa & Hanlin 2012, p. 184.
160. Kirk et al. 2008, p. 338.
161. Kirk et al. 2008, p. 231.
162. Kirk et al. 2008, p. 232.
163. Ulloa & Hanlin 2012, p. 185.
164. Ulloa & Hanlin 2012, p. 186.
165. Suryanarayanan & Thirunavukkarasu 2017, p. 1.
166. Ulloa & Hanlin 2012, p. 188.
167. Ulloa & Hanlin 2012, p. 190.
168. Kirk et al. 2008, p. 237.
169. Kirk et al. 2008, p. 240.
170. Ulloa & Hanlin 2012, p. 197.
171. Kirk et al. 2008, p. 241.
172. Kirk et al. 2008, p. 461.
173. Ulloa & Hanlin 2012, p. 199.
174. Ryan et al. 2022, page: Epiphloedal.
175. Galloway 2022.
176. Ulloa & Hanlin 2012, p. 200.
177. Øvstedal & Lewis Smith 2001, p. 369.
178. Ulloa & Hanlin 2012, p. 203.
179. Aptroot & Lücking 2016, p. 774.
180. Kirk et al. 2008, p. 246.
181. Cannon & Kirk 2007, p. 401.
182. Ryan et al. 2022, page: Eucortex.
183. Ulloa & Hanlin 2012, p. 211.
184. Ulloa & Hanlin 2012, pp. 207–208.
185. Ulloa & Hanlin 2012, p. 216.
186. Diederich, Lawrey & Ertz 2018, p. 342.
187. Ulloa & Hanlin 2012, pp. 216–217.
188. Brodo, Sharnoff & Sharnoff 2001, p. 758.
189. Ulloa & Hanlin 2012, p. 218.
190. Ulloa & Hanlin 2012, p. 219.
191. Moncada, Lücking & Betancourt-Macuase 2013, p. 2015.
192. Ulloa & Hanlin 2012, p. 220.
193. Ulloa & Hanlin 2012, p. 221.
194. Kirk et al. 2008, p. 256.
195. Cannon & Kirk 2007, p. 402.
196. Ulloa & Hanlin 2012, p. 222.
197. Ulloa & Hanlin 2012, p. 224.
198. Ulloa & Hanlin 2012, p. 225.
199. Ryan et al. 2022, page: Fissurine.
200. Rivas Plata et al. 2010, pp. 141–142.
201. Cannon & Kirk 2007, p. 412.
202. Ulloa & Hanlin 2012, p. 226.
203. Ulloa & Hanlin 2012, p. 227.
204. Ulloa & Hanlin 2012, p. 229.
205. Ulloa & Hanlin 2012, pp. 229–230.
206. Kirk et al. 2008, p. 260.
207. Rapai, McMullin & Newmaster 2012.
208. Fraser, Pouliot & van der Sluijs 2021.
209. Ulloa & Hanlin 2012, pp. 231.
210. Moncada, Lücking & Betancourt-Macuase 2013, p. 205.
211. Kirk et al. 2008, p. 263.
212. Ryan et al. 2022, wart page: Fruit wart.
213. Ulloa & Hanlin 2012, p. 239.
214. Ryan et al. 2022, page: Fuscocapitate.
215. Kirk et al. 2008, p. 270.
216. Ryan et al. 2022, page: Fuzzy coat.
217. Kirk et al. 2008, p. 271.
218. Büdel & Scheidegger 2008, p. 41.
219. Ulloa & Hanlin 2012, p. 247.
220. Ulloa & Hanlin 2012, p. 252.
221. Ulloa & Hanlin 2012, p. 255.
222. Ulloa & Hanlin 2012, p. 256.
223. Kirk et al. 2008, p. 288.
224. Ulloa & Hanlin 2012, p. 257.
225. Kirk et al. 2008, p. 290.
226. Ulloa & Hanlin 2012, p. 260.
227. Kirk et al. 2008, p. 294.
228. Ulloa & Hanlin 2012, p. 262.
229. Ulloa & Hanlin 2012, p. 263.
230. Ulloa & Hanlin 2012, p. 264.
231. Ryan et al. 2022, page: Hafter.
232. Ryan et al. 2022, page: Halo.
233. Ryan et al. 2022, page: Halonate.
234. Ulloa & Hanlin 2012, p. 268.
235. Ulloa & Hanlin 2012, p. 273.
236. Ulloa & Hanlin 2012, p. 274.
237. Ulloa & Hanlin 2012, p. 275.
238. Ulloa & Hanlin 2012, p. 278.
239. Ulloa & Hanlin 2012, p. 280.
240. Ulloa & Hanlin 2012, p. 282.
241. Ulloa & Hanlin 2012, p. 283.
242. Ulloa & Hanlin 2012, p. 284.
243. Ryan et al. 2022, page: Hormocyte.
244. Ulloa & Hanlin 2012, p. 285.
245. Ulloa & Hanlin 2012, p. 288.
246. Kirk et al. 2008, p. 328.
247. Ulloa & Hanlin 2012, p. 294.
248. Ulloa & Hanlin 2012, p. 295.
249. Goward 1986, p. 219.
250. Ulloa & Hanlin 2012, p. 296.
251. Kirk et al. 2008, p. 335.
252. MacKenzie Lamb 1968, p. 86.
253. Ulloa & Hanlin 2012, p. 301.
254. Ulloa & Hanlin 2012, p. 303.
255. Brodo, Sharnoff & Sharnoff 2001, p. 759.
256. Ryan et al. 2022, page: Inspers.
257. Ryan et al. 2022, page: Inspersion.
258. Ulloa & Hanlin 2012, p. 310.
259. Ulloa & Hanlin 2012, p. 313.
260. Randlane et al. 2009, p. 422.
261. Thüs & Schultz 2009, p. 17.
262. Ryan et al. 2022, page: Isotomic.
263. Ulloa & Hanlin 2012, p. 315.
264. Brodo 2016, p. 374.
265. Ahmadjian & Hale 1973, p. 636.
266. Ahmadjian & Hale 1973, p. 637.
267. Øvstedal & Lewis Smith 2001, p. 371.
268. Kirk et al. 2008, p. 358.
269. Ulloa & Hanlin 2012, p. 328.
270. Kirk et al. 2008, p. 359.
271. Krzewicka 2004, p. 7.
272. Rivas Plata et al. 2010, pp. 143–144.
273. Ryan et al. 2022, page: Lax.
274. Ulloa & Hanlin 2012, p. 336.
275. Ulloa & Hanlin 2012, p. 337.
276. Kirk et al. 2008, p. 367.
277. Rivas Plata et al. 2010, pp. 145–146.
278. Ulloa & Hanlin 2012, p. 339.
279. Kirk et al. 2008, p. 376.
280. Ulloa & Hanlin 2012, p. 341.
281. Kirk et al. 2008, p. 382.
282. Ulloa & Hanlin 2012, p. 346.
283. Ryan et al. 2022, page: Lirellate.
284. Kirk et al. 2008, p. 389.
285. Ulloa & Hanlin 2012, p. 347.
286. Brodo, Sharnoff & Sharnoff 2001, pp. 759–760.
287. Kirk et al. 2008, p. 391.
288. Ulloa & Hanlin 2012, p. 352.
289. Ulloa & Hanlin 2012, p. 357.
290. Ulloa & Hanlin 2012, p. 358.
291. Ahmadjian & Hale 1973, p. 46.
292. Brodo, Sharnoff & Sharnoff 2001, p. 760.
293. Kirk et al. 2008, p. 402.
294. Kirk et al. 2008, p. 412.
295. Meyer & Printzen 2000, pp. 581–582.
296. Rivas Plata et al. 2010, p. 582.
297. Ryan et al. 2022, page: Micareoid.
298. Orange, James & White 2001, p. 40.
299. Cannon & Kirk 2007, p. 414.
300. Ulloa & Hanlin 2012, p. 374.
301. Kirk et al. 2008, p. 435.
302. Kirk et al. 2008, p. 437.
303. Ulloa & Hanlin 2012, p. 389.
304. Ulloa & Hanlin 2012, p. 390.
305. Ulloa & Hanlin 2012, p. 392.
306. Cannon & Kirk 2007, p. 415.
307. Collins English Dictionary 2022a.
308. Nash 2008, p. 1.
309. Hawksworth 1988, pp. 4–5.
310. Kirk et al. 2008, p. 451.
311. Kirk et al. 2008, p. 477.
312. Ulloa & Hanlin 2012, p. 428.
313. Kirk et al. 2008, p. 479.
314. Ulloa & Hanlin 2012, p. 432.
315. Kirk et al. 2008, p. 488.
316. Ulloa & Hanlin 2012, p. 439.
317. Kirk et al. 2008, p. 489.
318. Ulloa & Hanlin 2012, p. 442.
319. Ulloa & Hanlin 2012, pp. 442–443.
320. Ulloa & Hanlin 2012, p. 444.
321. Ulloa & Hanlin 2012, p. 445.
322. Ulloa & Hanlin 2012, p. 446.
323. Cannon & Kirk 2007, p. 419.
324. Ulloa & Hanlin 2012, p. 448.
325. Ulloa & Hanlin 2012, pp. 448–449.
326. Ulloa & Hanlin 2012, p. 449.
327. Kirk et al. 2008, p. 497.
328. Ulloa & Hanlin 2012, p. 452.
329. Kirk et al. 2008, p. 503.
330. Ulloa & Hanlin 2012, p. 455.
331. Sérusiaux & Lücking 2007.
332. Ulloa & Hanlin 2012, p. 454.
333. Ulloa & Hanlin 2012, p. 457.
334. Kirk et al. 2008, p. 508.
335. Ulloa & Hanlin 2012, p. 459.
336. Ulloa & Hanlin 2012, p. 460.
337. Smith et al. 2009, p. 30.
338. Ulloa & Hanlin 2012, p. 463.
339. Mitchell 2014, p. 17.
340. Sanders 2004, p. 269.
341. Ryan et al. 2022, page: Phenocortex.
342. Collins English Dictionary 2022b.
343. Ulloa & Hanlin 2012, p. 471.
344. Laundon 1995.
345. Ulloa & Hanlin 2012, p. 470.
346. Kirk et al. 2008, p. 527.
347. Ulloa & Hanlin 2012, p. 475.
348. Kirk et al. 2008, p. 528.
349. Kistenich et al. 2018, p. 872.
350. Ulloa & Hanlin 2012, p. 482.
351. Jagtap, Tripathi & Joshi 2013, p. 342.
352. Rivas Plata et al. 2010, p. 143.
353. Kirk et al. 2008, p. 544.
354. Ulloa & Hanlin 2012, p. 487.
355. Ryan et al. 2022, page: Plicate.
356. Ulloa & Hanlin 2012, p. 490.
357. McCune & Wang 2014, p. 28.
358. Ulloa & Hanlin 2012, p. 492.
359. Kirk et al. 2008, p. 553.
360. Øvstedal & Lewis Smith 2001, p. 372.
361. Rivas Plata et al. 2010, pp. 148–149.
362. Kirk et al. 2008, p. 646.
363. Ryan et al. 2022, page: Prominent.
364. Kirk et al. 2008, pp. 250, 562.
365. Ulloa & Hanlin 2012, p. 506.
366. Ulloa & Hanlin 2012, p. 507.
367. Ulloa & Hanlin 2012, p. 510.
368. Ulloa & Hanlin 2012, p. 511.
369. Ryan et al. 2022, page: Pruina.
370. Kirk et al. 2008, p. 566.
371. Ryan et al. 2022, page: Pseudocortex.
372. Ulloa & Hanlin 2012, p. 513.
373. Kirk et al. 2008, p. 568.
374. Ulloa & Hanlin 2012, p. 514.
375. Ulloa & Hanlin 2012, p. 515.
376. Ulloa & Hanlin 2012, p. 517.
377. Smith et al. 2009, p. 36.
378. Kirk et al. 2008, p. 573.
379. Kirk et al. 2008, p. 581.
380. Kirk et al. 2008, p. 582.
381. Ulloa & Hanlin 2012, p. 522.
382. Ulloa & Hanlin 2012, p. 523.
383. Brodo, Sharnoff & Sharnoff 2001, p. 762.
384. Ulloa & Hanlin 2012, p. 525.
385. Cannon & Kirk 2007, p. 582.
386. Lumbsch & Huhndorf 2007.
387. Ulloa & Hanlin 2012, p. 526.
388. Ulloa & Hanlin 2012, p. 527.
389. Ulloa & Hanlin 2012, p. 533.
390. Kirk et al. 2008, p. 588.
391. Ulloa & Hanlin 2012, p. 541.
392. Ryan et al. 2022, page: Recurved.
393. Kirk et al. 2008, p. 595.
394. Ulloa & Hanlin 2012, p. 548.
395. Kirk et al. 2008, p. 597.
396. Smith et al. 2009, p. 38.
397. Ulloa & Hanlin 2012, p. 549.
398. Ulloa & Hanlin 2012, p. 552.
399. Ulloa & Hanlin 2012, p. 553.
400. Ulloa & Hanlin 2012, pp. 553–554.
401. Ulloa & Hanlin 2012, p. 555.
402. Kirk et al. 2008, p. 607.
403. Meyer & Printzen 2000, pp. 579–580.
404. Ulloa & Hanlin 2012, p. 558.
405. Kirk et al. 2008, p. 610.
406. Rivas Plata et al. 2010, p. 144.
407. Ulloa & Hanlin 2012, p. 565.
408. Ulloa & Hanlin 2012, p. 567.
409. Scott 1957, p. 487.
410. Kirk et al. 2008, p. 627.
411. Randlane et al. 2009, p. 423.
412. Ulloa & Hanlin 2012, p. 574.
413. Ryan et al. 2022, page: Seriate.
414. Kirk et al. 2008, p. 632.
415. Fjelde et al. 2024, p. 107944.
416. Ulloa & Hanlin 2012, p. 580.
417. Ulloa & Hanlin 2012, p. 581.
418. Kantvilas 2023.
419. Øvstedal & Lewis Smith 2001, p. 373.
420. Ulloa & Hanlin 2012, p. 586.
421. Kirk et al. 2008, p. 645.
422. Lücking, Leavitt & Hawksworth 2021.
423. Kirk et al. 2008, p. 647.
424. Ulloa & Hanlin 2012, p. 596.
425. Ulloa & Hanlin 2012, p. 598.
426. Ryan et al. 2022, page: Spongiostratum.
427. Kirk et al. 2008, p. 657.
428. Wirth & Hale Jr. 1978, p. 2, .
429. Smith et al. 2009, pp. 383–384.
430. Ahmadjian & Hale 1973, pp. 633–634.
431. Ulloa & Hanlin 2012, p. 610.
432. Brodo, Sharnoff & Sharnoff 2001, p. 763.
433. Ulloa & Hanlin 2012, p. 621.
434. Kirk et al. 2008, p. 670.
435. Kirk et al. 2008, p. 671.
436. Ulloa & Hanlin 2012, p. 625.
437. Ulloa & Hanlin 2012, p. 627.
438. Kirk et al. 2008, p. 672.
439. Ulloa & Hanlin 2012, p. 629.
440. Ulloa & Hanlin 2012, p. 639.
441. Smith 1921, p. xxii.
442. Smith 1921, p. 24.
443. Ulloa & Hanlin 2012, p. 642.
444. Thüs & Schultz 2009, p. 21.
445. Ulloa & Hanlin 2012, p. 644.
446. Kirk et al. 2008, pp. 250, 684.
447. Ulloa & Hanlin 2012, p. 646.
448. Ulloa & Hanlin 2012, p. 647.
449. Kirk et al. 2008, p. 684.
450. Poelt & Obermayer 1990.
451. Kantvilas & Jarman 1999, p. 206.
452. Dobson 2011, p. 482.
453. Kirk et al. 2008, p. 685.
454. Papong et al. 2010, p. 131.
455. Ulloa & Hanlin 2012, p. 171.
456. Ulloa & Hanlin 2012, p. 653.
457. Büdel & Scheidegger 2008, p. 54.
458. Rivas Plata et al. 2010, pp. 146–147.
459. Ryan et al. 2022, page: Trentepohlioid.
460. Ryan et al. 2022, page: Trebouxioid.
461. Ulloa & Hanlin 2012, p. 663.
462. Büdel & Scheidegger 2008, p. 43.
463. Ulloa & Hanlin 2012, p. 669.
464. Ulloa & Hanlin 2012, p. 670.
465. Ulloa & Hanlin 2012, p. 671.
466. Ulloa & Hanlin 2012, p. 673.
467. Ulloa & Hanlin 2012, p. 674.
468. Rivas Plata et al. 2010, p. 147.
469. Ulloa & Hanlin 2012, p. 675.
470. Thell et al. 2012, p. 655.
471. Orange, James & White 2001, pp. 10, 47.
472. Büdel & Scheidegger 2008, p. 46.
473. Ulloa & Hanlin 2012, p. 682.
474. Ulloa & Hanlin 2012, p. 683.
475. Ulloa & Hanlin 2012, p. 687.
476. Ryan et al. 2022, page: Verruciform.
477. Kirk et al. 2008, p. 724.
478. Australian National Herbarium.
479. Tripp 2017, p. 152.
480. Ulloa & Hanlin 2012, p. 700.
481. Kirk et al. 2008, p. 742.
482. "Record Details: Zeora Fr., Syst. orb. veg. (Lundae) 1: 244 (1825)". Index Fungorum. Retrieved 4 December 2022.
483. Ryan et al. 2022, page: Zeorine.
484. Cannon & Kirk 2007, p. 437.

Sources

• "Vitricolous lichens – Lichen website". Australian National Botanic Gardens - Botanical Web Portal. Australian National Herbarium. 20 October 2009. Retrieved 18 October 2022.
• "Definition of mycobiont". Collins English Dictionary. 2022a. Retrieved 23 July 2022.
• "Definition of phycobiont". Collins English Dictionary. 2022b. Retrieved 23 July 2022.
• Ahmadjian, Vernon; Hale, Mason E. (1973). The Lichens. New York: Academic Press. ISBN 978-0-12-044950-7.
• Ahti, T. (1982). "The morphological interpretation of cladoniiform thalli in lichens". The Lichenologist. 14 (2): 105–113. doi:10.1017/s0024282982000255.
• Aptroot, André; Lücking, Robert (2016). "A revisionary synopsis of the Trypetheliaceae (Ascomycota: Trypetheliales)". The Lichenologist. 48 (6): 763–982. doi:10.1017/s0024282916000487.
• Breuss, Othmar (2010). "An updated world-wide key to the catapyrenioid lichens (Verrucariaceae)". Herzogia. 23 (2): 205–216. doi:10.13158/heia.23.2.2010.205.
• Brodo, Irwin M.; Sharnoff, Sylvia Duran; Sharnoff, Stephen (2001). Lichens of North America. New Haven, Connecticut: Yale University Press. ISBN 0-300-08249-5.
• Brodo, Irwin (2016). "Glossary". Keys to Lichens of North America: Revised and Expanded. New Haven, Connecticut: Yale University Press. pp. 369–382. ISBN 978-0-300-19573-6.
• Cannon, Paul F.; Kirk, Paul M. (2007). Fungal Families of the World. Wallingford: CABI. ISBN 978-0-85199-827-5. OCLC 60741230.
• Diederich, Paul; Lawrey, James D.; Ertz, Damien (2018). "The 2018 classification and checklist of lichenicolous fungi, with 2000 non-lichenized, obligately lichenicolous taxa". The Bryologist. 121 (3): 340–425. doi:10.1639/0007-2745-121.3.340.
• Dobson, Frank S. (2011). Lichens: An Illustrated Guide to the British and Irish Species. Slough, UK: Richmond Publishing. ISBN 978-0-85546-315-1.
• Ferraro, Lidia Itatí (2004). "Morphological diversity in the hyphopores of Gomphillaceae (Ostropales, lichenized Ascomycetes)" (PDF). Fungal Diversity. 15: 153–169.
• Fjelde, Markus Osaland; Timdal, Einar; Haugan, Reidar; Bendiksby, Mika (2024). "Paraphyly and cryptic diversity unveils unexpected challenges in the "naked lichens" (Calvitimela, Lecanoromycetes, Ascomycota)". Molecular Phylogenetics and Evolution. 190: e107944. doi:10.1016/j.ympev.2023.107944. hdl:10852/106762.
• Fraser, Robert H.; Pouliot, Darren; van der Sluijs, Jurjen (2021). "UAV and high resolution satellite mapping of forage lichen (Cladonia spp.) in a rocky Canadian Shield landscape". Canadian Journal of Remote Sensing. 48 (1): 5–18. doi:10.1080/07038992.2021.1908118.
• Galloway, D.J. (6 June 2022). "Flora of Australia Glossary — Lichens". Australian Biological Resources Study. Retrieved 5 December 2022.
• Garrido-Benavent, Isaac; Pérez-Ortega, Sergio (2017). "Past, present, and future research in bipolar lichen-forming fungi and their photobionts". American Journal of Botany. 104 (11): 1660–1674. doi:10.3732/ajb.1700182.
• "Glossary of Terms". British Lichen Society. 2022. Retrieved 23 July 2022.
• Goward, Trevor (1986). "Brodoa, a new lichen genus in the Parmeliaceae". The Bryologist. 89 (3): 219–223. doi:10.2307/3243288. JSTOR 3243288.
• Grube, Martin; Hawksworth, David L. (2007). "Trouble with lichen: the re-evaluation and re-interpretation of thallus form and fruit body types in the molecular era". Mycological Research. 111 (9): 1116–1132. doi:10.1016/j.mycres.2007.04.008. PMID 17698333.
• Hafellner, Josef; Kalb, Klaus (1995). "Studies in Trichotheliales ordo novus". Studies in Lichenology with Emphasis on Chemotaxonomy, Geography and Phytochemistry. Festschrift Ch. Leuckert. Bibliothecia Lichenologica. Vol. 57. Berlin-Stuttgart: J. Cramer in der Gebrüder Borntraeger Verlagsbuchhandlung. pp. 161–186. ISBN 978-3-44-358036-0.
• Hawksworth, D. L. (1988). "The variety of fungal-algal symbioses, their evolutionary significance, and the nature of lichens". Botanical Journal of the Linnean Society. 96 (1): 3–20. doi:10.1111/j.1095-8339.1988.tb00623.x.
• Hertel, Hannes (2009). "A new key to cryptothalline species of the genus Lecidea (Lecanorales)". In Aptroot, A.; Seaward, M.R.D.; Sparrius, L.B. (eds.). Biodiversity and Ecology of Lichens – Liber Amicorum Harrie Sipman. Bibliotheca Lichenologica. Vol. 99. Berlin/Stuttgart: J.Cramer in der Gebrüder Borntraeger Verlagsbuchhandlung. pp. 185–204. ISBN 978-3-443-58078-0.
• Honegger, Rosmarie (1991). "Functional aspects of the lichen symbiosis". Annual Review of Plant Physiology and Plant Molecular Biology. 42 (1): 553–578. doi:10.1146/annurev.pp.42.060191.003005.
• Jagtap, Vineeta; Tripathi, Manish; Joshi, Yogesh (2013). "First report on the occurrence of plasticolous lichens from Uttarakhand, India" (PDF). Journal of Applied and Natural Science. 5 (2): 342–344. doi:10.31018/jans.v5i2.329.
• Kantvilas, G. & Jarman, S.J. (1999). Lichens of rainforest in Tasmania. Canberra, ACT, Australia: Australian Biological Resources Study. ISBN 0-642-56802-2.
• Kantvilas, Gintaras (2023). "Three new species of siphuloid lichens, with a first key to the genus Parasiphula". The Lichenologist. 55 (1): 17–25. doi:10.1017/s0024282922000421.
• Kirk, Paul M.; Cannon, Paul F.; Minter, David W.; Stalpers, Joost A., eds. (2008). Dictionary of the Fungi. Vol. 10. CAB International. ISBN 978-1-84593-933-5.
• Kistenich, Sonja; Timdal, Einar; Bendiksby, Mika; Ekman, Stefan (2018). "Molecular systematics and character evolution in the lichen family Ramalinaceae (Ascomycota: Lecanorales)". Taxon. 67 (5): 871–904. doi:10.12705/675.1. hdl:10852/67955.
• Korf, Richard P. (1962). "A synopsis of the Hemiphacidiaceae, a family of the Helotiales (Discomycetes) causing needle-blights of conifers". Mycotaxon. 54 (1): 12–33.
• Krzewicka, Beata (2004). "The lichen genera Lasallia and Umbilicaria in the Polish Tatra mts". Polish Botanical Studies. 17: 1–88.
• Laundon, Jack R. (1995). "On the classification of lichen photomorphs". Taxon. 44 (3): 387–389. doi:10.2307/1223409. JSTOR 1223409.
• Lendemer, James C.; Buck, William R.; Harris, Richard C. (September 2016). "Two new host-specific hepaticolous species of Catinaria (Ramalinaceae)". The Lichenologist. 48 (5): 441–449. doi:10.1017/S0024282916000438.
• Lücking, Robert; Leavitt, Steven D.; Hawksworth, David L. (2021). "Species in lichen-forming fungi: balancing between conceptual and practical considerations, and between phenotype and phylogenomics". Fungal Diversity. 109 (1): 99–154. doi:10.1007/s13225-021-00477-7.
• "Lichen Basics". North American Mycological Association. Retrieved 15 October 2022.
• Lumbsch, H. Thorsten; Huhndorf, Sabine M. (2007). "Whatever happened to the pyrenomycetes and loculoascomycetes?". Mycological Research. 111 (9): 1064–1074. doi:10.1016/j.mycres.2007.04.004.
• MacKenzie Lamb, I. (1968). "Appendix II. Glossary of Technical Terms". Antarctic Lichens. II. The Genera Buellia and Rinodina (Report). British Antarctic Survey Scientific Reports. British Antarctic Survey.
• McCune, B.; Wang, L.S. (2014). "The lichen genus Hypogymnia in southwest China". Mycosphere. 5 (1): 27–76. doi:10.5943/mycosphere/5/1/2.
• Mercado-Díaz, Joel A.; Gould, William A.; González, Grizelle; Lücking, Robert (2015). Lichens in Puerto Rico: an ecosystem approach. Gen. Tech. Rep. IITF-GTR-46 (Report). San Juan, Puerto Rico: United States Department of Agriculture, Forest Service, International Institute of Tropical Forestry.
• Meyer, Barbara; Printzen, Christian (2000). "Proposal for a standardized nomenclature and characterization of insoluble lichen pigments". The Lichenologist. 32 (6): 571–583. doi:10.1006/lich.2000.0294.
• Mitchell, M.E. (2014). "De Bary's legacy: the emergence of differing perspectives on lichen symbiosis" (PDF). Huntia. 15 (1): 5–22.
• Moncada, Bibiana; Lücking, Robert; Betancourt-Macuase, Luisa (2013). "Phylogeny of the Lobariaceae (lichenized Ascomycota: Peltigerales), with a reappraisal of the genus Lobariella". The Lichenologist. 45 (2): 203–263. doi:10.1017/s0024282912000825.
• Orange, A.; James, P.W.; White, F.J. (2001). Microchemical Methods for the Identification of Lichens. British Lichen Society. ISBN 978-0-9540418-0-9.
• Øvstedal, D.O.; Lewis Smith, R.I. (2001). "Glossary". Lichens of Antarctica and South Georgia. A Guide to Their Identification and Ecology. Cambridge, UK: Cambridge University Press. pp. 367–374. ISBN 978-0-521-66241-3.
• Poelt, J. (1980). "Physcia opuntiella spec. nov. und die Lebeusform der Sprosseuden Flechten" [Physcia opuntiella spec. nov. and the life form of the branching lichens]. Flora. 169 (1): 23–31. Bibcode:1980FMDFE.169...23P. doi:10.1016/s0367-2530(17)31162-3.
• Poelt, J.; Obermayer, W. (1990). "Über Thallosporen bei einigen Krustenflechten" [On thallospores in some crustose lichens]. Herzogia (in German). 8: 273–288. doi:10.1127/herzogia/8/1990/273.
• Rikkinen, Jouko (April 2015). "Cyanolichens". Biodiversity and Conservation. 24 (4): 973–993. Bibcode:2015BiCon..24..973R. doi:10.1007/s10531-015-0906-8.
• Nash III, Thomas H., ed. (2008). Lichen Biology (2nd ed.). Cambridge, UK: Cambridge University Press. ISBN 978-0-521-69216-8.

Nash, T.H. III (2008). "1. Introduction". In Nash III, Thomas H. (ed.). Lichen Biology (2nd ed.). Cambridge, UK: Cambridge University Press. pp. 1–8. ISBN 978-0-521-69216-8.

Honegger, R. (2008). "3.Mycobionts". In Nash III, Thomas H. (ed.). Lichen Biology (2nd ed.). Cambridge, UK: Cambridge University Press. pp. 27–39. ISBN 978-0-521-69216-8.

Büdel, B.; Scheidegger, C. (2008). "4.Thallus morphology and anatomy". In Nash III, Thomas H. (ed.). Lichen Biology (2nd ed.). Cambridge, UK: Cambridge University Press. pp. 40–68. ISBN 978-0-521-69216-8.

• Nelsen, Matthew P.; Lücking, Robert; Aptroot, André; Andrew, Carrie J.; Cáceres, Marcela; Plata, Eimy Rivas; Gueidan, Cécile; da Silva Canêz, Luciana; Knight, Allison; Ludwig, Lars R.; Mercado-Díaz, Joel A.; Parnmen, Sittiporn; Lumbsch, H. Thorsten (2014). "Elucidating phylogenetic relationships and genus-level classification within the fungal family Trypetheliaceae (Ascomycota: Dothideomycetes)". Taxon. 63 (5): 974–992. doi:10.12705/635.9.
• Nelsen, Matthew P.; Lücking, Robert; Boyce, C. Kevin; Lumbsch, H. Thorsten; Ree, Richard H. (2020). "The macroevolutionary dynamics of symbiotic and phenotypic diversification in lichens". Proceedings of the National Academy of Sciences. 117 (35): 21495–21503. Bibcode:2020PNAS..11721495N. doi:10.1073/pnas.2001913117. PMC 7474681. PMID 32796103.
• Papong, Khwanruan; Boonpragob, Kansri; Mangold, Armin; Divakar, Pradeep K.; Lumbsch, H. Thorsten (2010). "Thelotremoid lichen species recently described from Thailand: a re-evaluation". The Lichenologist. 42 (2): 131–137. doi:10.1017/s0024282909990405.
• Randlane, Tiina; Tõrra, Tiiu; Saag, Andres; Saag, Lauri (2009). "Key to European Usnea species". In Thell, Arne; Seaward, Mark R. D.; Feuerer, Tassilo (eds.). Diversity of Lichenology – Anniversary Volume. Bibliotheca Lichenologica. Vol. 100. Stuttgart: J. Kramer. pp. 419–462. ISBN 978-3-443-58079-7.
• Rapai, Sean B.; McMullin, Richard Troy; Newmaster, Steven G. (2012). "The importance of macrolichen traits and phylogeny in forest community assemblage along a high elevation gradient in southwestern British Columbia". Forest Ecology and Management. 274: 231–240. Bibcode:2012ForEM.274..231R. doi:10.1016/j.foreco.2012.02.018.
• Rivas Plata, Eimy; Lücking, Robert; Sipman, Harrie J. M.; Mangold, Armin; Kalb, Klaus; Lumbsch, H. Thorsten (2010). "A world-wide key to the thelotremoid Graphidaceae, excluding the Ocellularia-Myriotrema-Stegobolus clade". The Lichenologist. 42 (2): 139–185. doi:10.1017/s0024282909990491.
• Ryan, B.D.; Bungartz, F.; Hagedorn, G.; Rambold, G., eds. (2022). "LIAS glossary – A Wiki-based Online Dictionary for Ascomycete Terminology used by LIAS, the Global Information System for Lichenized and Non-Lichenized Ascomycetes". LIAS Glossary.
• Sanders, William B. (2004). "Bacteria, algae, and phycobionts: maintaining useful concepts and terminology". The Lichenologist. 36 (5): 269–275. doi:10.1017/s0024282904014343.
• Scott, G.D. (1957). "Lichen terminology". Nature. 179 (4557): 486–487. Bibcode:1957Natur.179..486S. doi:10.1038/179486b0. PMID 13407756.
• Sérusiaux, E.; Lücking, R. (2007). "Gallaicolichen, a new genus of foliicolous lichen with unique diaspores". In Kärnefelt, Ingvar; Thell, Arne (eds.). Lichenological Contributions in Honour of David Galloway. Bibliotheca Lichenologica. Vol. 95. Berlin/Stuttgart: J. Cramer. pp. 509–516. ISBN 978-3-443-58074-2.
• Smith, C.W.; Aptroot, A.; Coppins, B.J.; Fletcher, A.; Gilbert, O.L.; James, P.W.; Wolseley, P.A., eds. (2009). "Glossary". The Lichens of Great Britain and Ireland. London: British Lichen Society. pp. 21–39.
• Suryanarayanan, Trichur S.; Thirunavukkarasu, Nagamani (2017). "Endolichenic fungi: the lesser known fungal associates of lichens". Mycology. 8 (3): 189–196. doi:10.1080/21501203.2017.1352048. PMC 6059131. PMID 30123639.
• Upreti, Dalip K.; Rai, Himanshu, eds. (2013). Terricolous Lichens in India. Vol. 1: Diversity Patterns and Distribution Ecology. New York: Springer. ISBN 978-1-4614-8736-4.
• Silverstein, Alvin; Silverstein, Virginia B.; Silverstein, Robert A. (1996). Fungi. New York: Twenty-First Century Books. ISBN 0-8050-3520-6.
• Smith, Annie Lorrain (1921). Lichens. London: Cambridge University Press. pp. 1–504.
• Thell, Arne; Crespo, Ana; Divakar, Pradeep K.; Kärnefelt, Ingvar; Leavitt, Steven D.; Lumbsch, H. Thorsten; Seaward, Mark R.D. (2012). "A review of the lichen family Parmeliaceae – history, phylogeny and current taxonomy". Nordic Journal of Botany. 30 (6): 641–664. doi:10.1111/j.1756-1051.2012.00008.x.
• Thüs, Holger; Schultz, Matthias (2009). "Glossary". In Büdel, Burkhard; Gärtner, Georg; Krienitz, Lothar; Preisig, Hans R.; Schagerl, Michael (eds.). Fungi. Part 1: Lichens. Süßwasserflora von Mitteleuropa [Freshwater Flora of Central Europe]. Vol. 21/1. Heidelberg: Spektrum Akademischer Verlag. pp. 14–23. doi:10.1007/978-3-8274-2299-6_2. ISBN 978-3-8274-1594-3.
• Tripp, Erin (2017). Field Guide to the Lichens of White Rocks (Boulder, Colorado). University Press of Colorado. ISBN 978-1-60732-554-3.
• Ulloa, Miguel; Hanlin, Richard T. (2012). Illustrated Dictionary of Mycology (2nd ed.). St. Paul, Minnesota: The American Phytopathological Society. ISBN 978-0-89054-400-6.
• Vondrák, Jan; Svoboda, Stanislav; Zíbarová, Lucie; Štenclová, Lenka; Mareš, Jan; Pouska, Václav; Košnar, Jiří; Kubásek, Jiří (2023). "Alcobiosis, an algal-fungal association on the threshold of lichenisation". Scientific Reports. 13 (2957): 2957. Bibcode:2023NatSR..13.2957V. doi:10.1038/s41598-023-29384-4. PMC 9975235. PMID 36854763.
• Weber, Bettina; Büdel, Burkhard (2011). "Endoliths". Encyclopedia of Geobiology. Dordrecht: Springer Netherlands. pp. 348–355. doi:10.1007/978-1-4020-9212-1_80. ISBN 978-1-4020-9211-4.
• Wirth, M.; Hale Jr., M.E. (1978). Morden-Smithsonian Expedition to Dominica: The Lichens (Graphidaceae). Smithsonian Contributions to Botany. Vol. 40. pp. 1–64.