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In the bud, Tetradenia riparia leaves have their upper surfaces turned toward the stem and the axil. The lower surface is abaxial ("away from the axis"), and the upper surface is adaxial.
Geranium incanum flowers are actinomorphic, having five axes of symmetry, as opposed to the two axes of symmetry of the zygomorphic flowers of most species of the related genus Pelargonium.
Specialized layer of tissue that allows an organ to be shed by abscission when it is ripe or senescent. Such tissue is commonly formed, for example, at the base of a petiole or pedicel.
Lying against another part of the plant; when applied to a cotyledon, it means that an edge of the cotyledon lies along the folded radicle in the seed.[8]
Dry, one-seeded indehiscentfruit[11] in which the true fruit is not the so-called "berry", but the achenes, which are the so-called "seeds" on the infructescence, e.g. in the genus Fragaria.
Having organs, particularly filaments such as stamens, connected into one or more adelphiae, whether in the form of bunches or tubes, such as is commonly seen in families such as Malvaceae. Usage of the term is not consistent; some authors include closely bunched filaments, while others include only adelphiae in which filaments are connected minimally at their bases. See, for example, Sims: "...the filaments are so closely pressed that they have the appearance of being monadelphous...".[14] Compare derived terms such as monadelphous, having stamens growing in a single bunch or tube, for example in Hibiscus, and diadelphous, growing in two bunches.
adherent
Slightly united to an organ of another kind,[13] usually to a part of another whorl, e.g. a sepal connected to a petal. Contrast adnate.
Grown from or closely fused to an organ of a different kind,[13] especially along a margin, e.g. a stamen fused to a petal. Adnate anthers have their halves attached to the filament through most of their length. Contrast connate.
Produced in an unpredictable or unusual position,[13] e.g. an adventitious bud produced from a stem rather than from the more typical axil of a leaf. Adventitious roots may develop from nodes of prostrate stems of some plant species, or from the hypocotyl rather than from the radicle of a germinating monocotyledon.
With affinity to others, akin to; often used for a provisionally recognized but unnamed taxon considered close to that name, perhaps a hybrid or extreme variant.
Plant species that have invaded native vegetation and could survive there without human intervention. They are established there in natural habitats, remaining part of natural vegetation even after human influence has ceased, and are independent of humans in their continued existence.[16]
agrophic
Comb-like series of veins forking from a single side of a primary or secondary vein.
The scientific study of grasses, in the strictest sense only those species which are members of the family Poaceae. Broader usages sometimes also include grass-like or graminoid species from the families Cyperaceae, Juncaceae, and Typhaceae.
Older name for the endosperm of flowering plants. Except for being a storage tissue for nutrients, it is not like the albumen (egg white) of animal embryos.
Any plant introduced to an area outside its natural range. Often used interchangeably or in combination with foreign, exotic, non-native, and non-indigenous.
Any of a loosely defined class of organic compounds found in the tissues of many species of plants. Alkaloid molecules have one or more alkaline-reacting nitrogen atoms in their carbon structures. Many alkaloids are commercially important as drugs or poisons, e.g. caffeine, morphine, quinine, and strychnine, each of which occurs naturally in certain plants.
A collective name for the male reproductive parts of a flower; the stamens of a flower considered collectively. Contrast gynoecium. Abbreviated A; e.g. A 3+3 indicates six stamens in two whorls.
1.A ring-like structure; in the form of a ring. Pappus bristles are sometimes attached to a ring called an annulus or disk at the top of the achene beak. In some pollen grains, the exine around the apertures is either thicker or thinner. In pores, this border is termed an annulus. Certain flowers have ring-like constrictions at the mouth of the flower, e.g. in Huernia and Aristolochia.
1.(of a flower) The period during which pollen is presented and/or the stigma is receptive.
2.(of a flowering plant) The period during which flowers in anthesis are present. Not defined for some cases, such as when pollen is released in the bud.
A type of asexual reproduction whereby viable seeds or spores are produced asexually, without fertilization, such that the genetic material they contain is a clone of the parent's genetic material. A plant produced in this way is called an apomict.
A plant whose natural habitat is water, living in or on water for all or a substantial part of its lifespan; generally restricted to fresh or inland waters.
A multicellular haploid structure or organ of the gametophyte phase of certain plants, producing and containing the ovum or female gamete. The corresponding male organ is called the antheridium.
archegoniophore
In liverworts of the order Marchantiales, a female gametophore: a specialized, stalked structure that bears the archegonia and the sporophytes.
arctotoid
In the Compositae, a style with a ring of sweeping hairs borne on the shaft of the style proximal to the style branches.
1.A space between the threads of a net, e.g. that part of a leaf surface defined by each of the elements of a vein network; as with cacti, the area between the veinlets of a leaf.
2.A structure on the stem node of a cactus, morphologically a specialised branch; the region of a cactus upon which spines, glochids, and flowers are borne.
A membranous or fleshy appendage formed by expansion of the funicle which partly or wholly covers a seed, e.g. the fleshy outer layer of lychee fruit, or that found in members of the Sapindaceae.
With a stiff, bristle-like awn or tip. See also Leaf shape.
article
A segment of a jointed stem or of a fruit with constrictions between the seeds; an organ part that separates easily from the rest of the organ at a joint or articulation.
articulate
Jointed; separating freely, leaving a clean scar; e.g. the fronds of certain ferns where they join the rhizome.
ascending
1.(of a stem) Spreading horizontally, then directed upward; an ascending stem is more or less prostrate near its base, then erect.
2.In the Poaceae, an appendage terminating or on the back of glumes or lemmas of some grass spikelets.
3.In the Geraniaceae, the part of the style that remains attached to the carpel that separates from the carpophore (column).
4.A generally straight, stiff pappus element, varying from stiffly bristle-like to hard and needle-like. In Strophanthus, the awn is the beak of the seed, stipe of the coma hairs.
The protective external layer of tissue on the stems and roots of woody trees and shrubs; includes all of the living and non-living tissue external to the cambium.
basal
Situated or attached at or close to the base (of a plant or a phylogenetic tree diagram).
Developing sequentially from the apex toward the base (i.e. with the youngest toward the base), e.g. of flowers in an inflorescence. Also, moving from leaves to roots, e.g. of molecular signals in plants.
bathyphyll
A specialized leaf produced at the base of a plant, usually when the plant is immature, and which serves to anchor the plant to a substrate; especially notable in the fern Teratophyllum. Contrast acrophyll.
beak
A prominent, pointed terminal projection, especially of a carpel or fruit.
A plant which completes its life cycle (i.e. germinates, reproduces, and dies) within two years or growing seasons. Biennial plants usually form a basal rosette of leaves in the first year and then flower and fruit in the second year.
bifid
Forked; cut in two for about half its length. Compare trifid.
Making use of names consisting of two words to form the scientific name (or combination) in a Latin form. For example, where the first is the name of the genus to which the species belongs, and the second is the specific epithet given to that species to distinguish it from others in the same genus.
The system of nomenclature in which the scientific name of a species (and not of a taxon at any other rank) is a combination of two names, the first name being the generic name. The second name is referred to botanically as the specific epithet. Note that the two names together (not just the second name) constitute the species name.
The trunk of a tree, usually the portion below the lowest branch. Compare canopy.
bostrychoid
Arranged on a conical surface (like a snail shell); used to describe inflorescences in which the buds are arranged in an almost helical manner on the outside of a long, tapering, conical rachis.
A straight, stiff hair (smooth or with minute teeth); the upper part of an awn (when the latter is bent and has a lower, stouter, and usually twisted part, called the column).
Width of one lumen of a pollen grain reticulum and half of the width of the surrounding muri (walls), hence heterobrochate and homobrochate, where the lumina are of different or similar sizes, respectively.
The so-called "fleshy leaves" of cacti, such as on this Opuntia tomentosa, are actually cladodes (branches). The true leaves are the spines growing on the cladodes, which on this young cladode are still fleshy.
GamopetalousWatsonia flower split open between two petals to show the connate formation of the corolla tube; compare the adnate attachment of the stamen bases to the matching petals
Corms, one entire in its tunic, one partly peeled to show tunic cataphylls, and one split to show inner structure
Cotyledons of seedlings of Koelreuteria. One plant shows the first new leaves above its cotyledons, and the rest show various younger stages of emerging cotyledons.
2.Undifferentiated tissue growth formed in response to wounding; may be grown in vitro.
3.In orchids, fleshy outgrowths from the labellum which can be variously shaped from papillae to plates.
4.In grasses, a hardened extension from the base of a floret (formed from the rachilla joint and/or the base of the lemma), which may or may not elongate and is often covered in hairs or bristles.
Leaf-like structure formed from a sepal or calyx lobe which enlarges, usually many-fold, before or after anthesis, especially when most of the other sepals or calyx lobes retain their original size. More extreme than an accrescent calyx, calycophylls are found in Rubiaceae. Compare semaphyll and pterophyll.
Pinnatevenation in which the secondary veins curve toward the margins, in some cases becoming nearly parallel with them, and not reconnecting with other veins to form loops.
The basic female reproductive organ in angiosperms, either consisting of a single sporophyll or a single locule of a compound ovary, with a style and a stigma. The gynoecium is the collective term for all of the carpels of a single flower.
carpellary
Referring to carpels or to associated structures or outgrowths of carpels, for example staminodes attached to carpels in Nymphaeaceae, were frequently referred to as carpellary attachments. The current and past usage of the terms "carpellary attachments", paracarpels, and staminodes is confused and varies among authors.
A continuous band of suberin in the radial primary cell walls of the endodermis in vascular plant stems and roots that forms a permeability barrier to the passive diffusion of external water and solutes into the vascular tissue.
cassideous
Hood-, helmet- or bonnet-shaped; generally referring to floral anatomy, e.g. in the flowers of Aconitum, Satyrium, etc.
An exotic plant that appears with no apparent human assistance but does not develop a sustained population(s), or one that persists only by repeated new introductions. Compare alien.
Any plant structure which is morphologically a leaf but which has at most an incidental or transient photosynthetic function. They are either shed when their main function has been completed, or are incorporated into structures where, when dead, they serve a protective or supportive purpose.
The stem of a plant, especially a woody one; also used to mean a rootstock, or particularly a basal stem structure or storage organ from which new growth arises. Compare lignotuber.
Of a two-branched organ attached by its center, e.g. a hair or anther.
ceraceous
Having a waxy appearance, color, or texture, e.g. flowers of many species of Ceropegia, and the waxy fruit of some species of Myrica.
cernuous
Nodding, falling headlong or face down; inclined, stooping, or bowing forward. Applied to many species with a nodding, stooping habit, such as many Narcissus and Dierama species. Many plant species bear the specific epithet "cernua".
An individual composed of two or more genetically distinct tissues, most commonly as a result of a graft and sometimes by mutations that occur during cell division or cellular transfers during seed development.
Very small hairs or hair-like protrusions more or less confined to the margins of an organ, as with eyelashes; in motile cells, minute, hair-like protrusions which aid motility.
A single cell with multiple nuclei, formed when nuclear division was not followed by cytokinesis.
coleoptile
One type of sheath in the structure of monocotyledonous seeds. The coleoptile is a protective sheath or cap (pileus), generally more or less pointed, that covers the monocotyledonous plumule as it emerges from the soil. It generally turns green and contributes to photosynthesis until its function is superseded by the main growth of the seedling. Contrast this with the coleorhiza, which remains underground until it is superseded as the roots emerge.
coleorhiza
One type of sheath in the structure of monocotyledonous seeds. The coleorhiza connects the coleoptile to the radicle and protects the monocotyledonous radicle during germination. Unlike the coleoptile, the coleorhiza is associated with the root and does not emerge from the soil during germination. Contrast coleoptile.
A specialized tissue consisting of living cells with unevenly thickened cellulose and pectincell walls that performs a support function in organs such as leaves and young stems that are composed of primary plant tissues.
A multicellular, glandular hair that usually produces a mucilaginous substance and is located on sepals, stipules, or petioles, or on nearby parts of stems; commonly found on plants in the order Gentianales.
A name often of no botanical standing and not governed by the ICNCP. The term generally applies to names such as Trademark Names, names covered by Plant Breeders Rights, Patents and Promotional Names, which are often used to enhance the sale of a plant.
An ecological assemblage of plants that characteristically occur together.
compound
Composed of several parts, e.g. a leaf composed of multiple leaflets, a gynoecium composed of multiple carpels, or an inflorescence made up of multiple smaller inflorescences.
compound palmate
Having leaflets that radiate from a central point (usually at the top of a petiole), like spread-out fingers radiating from the palm of a hand. Compare palmate.
compressed
Flattened lengthwise, either laterally (from side to side) or dorsally (from front to back).
A rarely used term describing substantial differences between the overall structure of an inflorescence and that of its individual branches, e.g. the bottlebrush multiple-flower head of members of the genus Callistemon.
(of sepals or petals) A type of imbricate aestivation in which one side of each segment overlaps one of the adjacent segments and the other side is overlapped by the other adjacent segment. See convolute.
1.Referring to the arrangement of floral or foliar organs in a bud when each organ or segment has one edge overlapping the adjacent organ or segment; a form of imbricate arrangement. See contort.
2.(of leaves) A type of vernation in which one leaf is rolled up inside another.
3.A type of vernation of two leaves at a node, in which one half of each leaf is exposed and the other half is wrapped inside the other leaf.
A fleshy, swollen stem base, usually underground and functioning in the storage of food reserves, with buds naked or covered by very thin scales; a type of rootstock.
1.In flowering plants, a ring of structures that may be united in a tube, arising from the corolla or perianth of a flower and standing between the perianth lobes and the stamens. The trumpet of a daffodil is a corona.
2.In grasses, a hardened ring of tissue surmounting the lemma in some species.
Any of the "lower plants" which produce spores and do not have stamens, ovaries, or seeds; literally, plants whose sexual reproductive organs are not conspicuous. This group typically includes the ferns, bryophytes, and algae, and sometimes fungi (including lichenized fungi). Compare phanerogam.
cucullate
Hood-like or hooded, commonly referring to the shape of leaves or petals, e.g. Pelargonium cucullatum. Similarly derived terms include cuculliform and cuccularis.
A term derived from "cultivated variety" denoting an assemblage of cultivated plants clearly distinguished by one or more characters (morphological, physiological, cytological, chemical, or other). When reproduced (either sexually or asexually), the assemblage retains its distinguishing characters. A cultivar may arise in cultivation or be introduced from the wild. It is a variant that is of horticultural interest or value. Cultivar names are written with single quotation marks around them, e.g. 'Blue Carpet' or 'Alba'. All new names established after 1 January 1959 must be in common language (that is, not in Latin), but names established in Latin prior to this date are retained in Latin form.
cultivar epithet
The defining part of a name that denominates a cultivar. Cultivars are designated by fancy (q.v.) epithets appended either to the scientific name or to the common name of the taxon to which they belong; they are not italicized but placed in single quotation marks, e.g. Rubus nitidoides 'Merton Early'. 'Merton Early' is the cultivar epithet.
cuneate
Wedge-shaped, with straight sides converging at a base.
In Euphorbia, the bract-like structure on which the involucre sits, usually but not always occurring in twos. They may sometimes be brightly colored and confused with petals.
cylindrical
Rod-like and two to three times as long as wide. Compare baculiform.
Curving downward, and then upward at the tip. Often qualified, e.g. declinate-ascendant.
decompound
Divided to more than one level, e.g. in bipinnate leaves, in which the leaflets of what would otherwise be a pinnate leaf are themselves pinnately divided.
decorticate
1.(intr. v.) To shed the outer bark of a tree, usually seasonally as part of the natural growth cycle.
2.(tr. v.) To strip the peel, crust, bark, or other surface tissues from a plant or from harvested material, such as in extracting fiber from harvested Agave leaves.
decumbent
Having branches growing horizontally along the ground but which are turned up at the ends.
Extending downward beyond the point of insertion, e.g. when the base of a leaf or a fungal gill is prolonged downward along the stem in a raised line or narrow wing.
decussant
A synonym of decussate; the usage decussant is questionable and occurs rarely, probably as an error. The formally correct usage is decussate.
Any reproductive part of a plant adapted for dispersal and for establishing new plants; may be a disseminule such as a seed, or other parts such as specialized buds, branches, inflorescences, or fruits.
Forking into two equal branches. This may result from an equal division of the growing tip, or may be sympodial, in which the growing tip is aborted and replaced. Typically refers to mode of branch growth, as in Aloidendron dichotomum, but also to other organs, such as the venation patterns on leaves, the thorns of various species of Carissa (which morphologically are branches), and the thalli or hyphae of various algae and fungi.
Occurring in two different forms (with respect to shape and/or size), e.g. of stamens, fronds, or leaves. See also monomorphic (having a single form) and polymorphic (having many forms).
(of vascular plants) Having male and female reproductive structures which develop only on different individuals and never on the same individual. Contrast monoecious.
(of a bryophytegametophyte) Having male and female reproductive structures which develop only on different individuals and never on the same individual. Contrast monoicous.
Having two complete sets of chromosomes in the nucleus of a sporophyte cell, i.e. one set from each of the parental gametes. This is often expressed symbolically as 2n, where n = the number of chromosomes in the haploid gamete.
A plate or ring of structures derived from the receptacle, and occurring between whorls of floral parts. In some groups, especially Sapindales, the nectary is in the form of a prominent disk. In daisies, the central part of the capitulum is a disk, hence flowers borne there are called disk flowers or florets.
discoid
Resembling a disc or plate, having both thickness and parallel faces and with a rounded margin. Also used to describe the flower head of Asteraceae where there are no ray florets but only disc florets.
discolorous
(of leaves) Having upper and lower surfaces of different colors.
Occurring in widely separated geographic areas, distinctly separate; applies to a discontinuous range in which one or more populations are separated from other potentially interbreeding populations with sufficient distance so as to preclude gene flow between them.
disk floret
A floret occurring most typically in the disk of the capitulum of flowers in the family Asteraceae, and to some extent in other plants that bear a flowering head with a disk, such as Scabiosa.
dissected
Deeply divided; cut into many segments.
dissepiment
A partition or septum in a plant part, usually referring to septa between the loculi of capsules or of other fruits with multiple partitions.
The condition in which the flowers of a species occur in two forms that differ only by the length of the style and stamens, and flowers of only one of these forms appear on any one plant. Compare heterostyly.
A taxonomic rank below kingdom in the standard taxonomic hierarchy. "Division" is generally used only for plants, and is the approximate botanical equivalent of the term phylum, which is used for animals and other kingdoms.
From Latin dorsum, a ridge or the back of an animal. Partly because the term originally referred to animals rather than plants, usage in botany is arbitrary according to context and source. In general "dorsal" refers to "the rear or back or upper surface", but in botanical usage such concepts are not always clearly defined and may be contradictory. For example:
facing away from the axis (abaxial) in a lateral organ of an erect plant
facing away from the substrate in any part of an erect plant, for example the upper surface of a more or less horizontal leaf (adaxial) or the upper part of the crown of the plant
facing away from the substrate in a prostrate or climbing plant or floating leaves such as those of Nymphaea.
A long, narrow, acuminate, caudate, or cuspidate extension at the tip of a leaf or leaflet. Commonly an adaptation to rainy conditions, as it promotes shedding of water by its dripping from the narrow tip. The term drip tip is not anatomically descriptive in the way that acuminate or cuspidate are, for example; rather, it is a description of the functional shape that aids dripping, regardless of the specific geometry of the shape itself.
A type of succulentfruit formed from one carpel; the single seed is enclosed by a stony layer of the fruit wall, e.g. in peaches and olives. Also called a kernel.
A small drupe formed from one of the carpels in an apocarpous flower. Drupelets usually form a compound fruit, as in Rubus, but they may become widely separated, as in Ochna.
Plants of the genus Corydalis bear seeds with attached elaiosomes, which have various functions, commonly attracting ants. On some Corydalis species, elaiosomes that attract ants also repel mice.[32]
Ficus lyrata is an example of a doubly-emarginate leaf with lateral and apical emargination; it also might be seen as a basally emarginate.
Petals of Heracleum sphondylium are variously emarginate at their tips. Flowers in the middle of the inflorescence have slightly emarginate petals, whereas flowers at the periphery are so deeply emarginate as to be almost cleft in two.
The pale embryo emerging from the upper surface of the sprouting date seed is tiny in comparison to the endosperm, its main food supply, which comprises almost all of the rest of the seed.
An external structure attached to the seed of many species of plants. Elaiosomes generally look fleshy and in some species they are rich in oils or other nutritious materials. Their functions vary and are not always obvious; commonly they attract ants or other animals that aid in dispersal, but they may also repel other animals from eating the seed.[32]
Typically in reference to leaf margins: notched or recessed at some part of the edge, such as the apex; the recess usually is broad and shallow. The location of a leaf's emargination(s) might be one or more of apical, lateral or basal
A plant taller than the surrounding vegetation or, among aquatic plant species, one that bears flowers and commonly leaves above the surface of the water. Aquatic examples include water lilies, reeds, and papyrus. Some pondweeds such as Stuckenia are not emergent until they flower, at which time only their flowers appear above the water surface.
Species of recent appearance, usually numerous and constant in the country, but confined to artificial habitats, such as meadows and ruderal vegetation and are dependent on humans for existence.[34]
Borne on the ovary; describes floral parts when attached above the level of the ovary and arising from tissue fused to the ovary wall. Compare hypogynous and perigynous.
The adjectival component in a binomial scientific name, usually more specifically called a specific epithet; the final word or combination of words in a name of more than one word (other than a term denoting rank) that denominates an individual taxon. The simplest and commonest example is the second word in a two-word name of a species, such as "mirabilis" in Welwitschia mirabilis.
epizoochory
A type of seed dispersal that occurs when seeds or fruits physically adhere to the outside of vertebrate animal bodies.
In nomenclature, indicating that the preceding author proposed the name but did not legitimately publish it, and that the succeeding author referred to the first author when legitimately publishing the name. See Author citation (botany).
In the wild, the leaves of Fenestraria commonly are covered in soil, except for the transparent fenestration; this permits photosynthesis while reducing damage from exposure to intrense sunlight and herbivores.
A plant breeding term for the result of a plant arising from a cross between two F1 hybrids; may also refer to self-pollination in a population of F1 hybrids.
1.In Plant morphology, the habit of a plant that consists in part, of a bundle of erect, more or less parallel branches or stems, particularly if they form or taper to a peak or point. (Latin fastigiatus,meaning "having a peak".
2.In palynology, the form of a pollen grain that has a fastigium, a pointed apex over a hollow between the layers of the pollen outer wall.
The throat of a calyx or corolla; the conspicuously widened portion between the mouth and the apex of the tube. In Boraginaceae, the site of distinctive appendages.
Having translucent or transparent areas that let light through; this variously affects the behavior of animal visitors or permits photosynthesis in many arid-region plants that grow only to the soil surface. Also refers loosely to perforations, for which perforate is the more precise term.
2.Any flexible, strong, stringy, and very elongate structure.
fiber cell
A type of cell that is found in sclerenchyma; it is much elongated, and dies soon after an extensive modification of its cell wall. The cell wall is usually thickly lignified but is sometimes gelatinous.
1.All the plants growing in a certain region or country.
2.An enumeration of them, generally with a guide to their identification (e.g. the Flora of North America, Flora of China, Flora of Victoria, Flora of New South Wales, and so on). In this case, flora is written with a capital F.
A taxonomic category subordinate to species and within the taxonomic hierarchy, below variety (varietas), and usually differentiated by a minor character.
Specialized structures on the gametophytes of some bryophyte species, for example many species in the order Marchantiales; in such species the gametes are produced on the gametophores.
The haploid multicellular phase in the alternation of generations of plants and algae that bears gametes. In bryophytes the gametophyte is the dominant vegetative phase; in ferns and their allies it is a small free-living plant known as the prothallus; in gymnosperms and angiosperms the gametophytes are reduced to microscopic structures dependent on the sporophyte, male gametophytes contained in pollen grains and females contained within the ovules.
A group of one or more species with features or ancestry (or both) in common. Genus is the principal category of taxa intermediate in rank between family and species in the standard nomenclatural hierarchy.
Describing the external surface of a plant part that has a whitish covering, in some cases with a blueish cast. Often applied to plants with a wooly or arachnoid surface, but properly referring to pruinose surfaces, meaning those with a waxy bloom. The surfaces of the young leaves of many eucalypts provide good examples, and so do some xerophytes.
bracts subtending the floret(s) of a sedge, or similar plant; in grasses forming the lowermost organs of a spikelet (there are usually 2 but 1 is sometimes reduced; or rarely, both are absent).
A taxon whose members consist of tissue from two or more different plants in intimate association originated by grafting. The addition sign "+" is used to indicate a graft-chimaera either as a part of a formula (e.g. Crataegus monogyna + Mespilus germanica) or in front of an abbreviated name (e.g. + Crataegomespilus 'Dardari'). The nomenclature of graft hybrids is governed by the International Code of Nomenclature for Cultivated Plants.
A formal category equivalent to or below the rank of genus which distinguishes
an assemblage of two or more cultivars within a species or hybrid;
plants derived from a hybrid in which one or more of the parent species is not known or is of uncertain origin; or,
a range of cultivated plants of a species or hybrid which may exhibit variation but share one or more characters, which makes it worth distinguishing them as a unit.
A seed-bearing plant with unenclosed ovules borne on the surface of a sporophyll. Gymnosperms are among the oldest clades of vascular plants, and today are represented by approximately 1,000 extant species worldwide, including, among others, conifers, Ginkgo, Gnetum and cycads. Compare angiosperm.
The collective term for the female reproductive parts of a flower or for the carpels of a flower, whether united or free. Contrast androecium. Abbreviation: G. For instance, G indicates a superior ovary; G(5) indicates having five fused carpels.
Heteroblastic growth is common in Eucalyptus species with leaves that are isobilateral in the mature tree; they generally start life with dorsiventral leaves. Some of these saplings are in the transient stage in which they have both forms of leaves, dorsiventral on lower branches, and isobilateral above.
The hilum contrasts conspicuously with the rest of the testa in the seeds of many species. In the case of Erythrina species, the colors may be a warning that the seeds are poisonous.
Flowers, fruit and propagule of a Rhizophora "mangle" or mangrove. The apparent root of the propagule is in fact meristematic tissue developing from the hypocotyl. The new plant develops largely from this tissue, especially if it has successfully penetrated into mud in which the new plant can establish itself.
Having one set of chromosomes, e.g. the complement of chromosomes in each of the cells of the gametophyte, the nucleus of a gamete, and the spores. This is expressed symbolically as n, where n = the gametic number of chromosomes. Compare diploid, triploid, and tetraploid.
Triangular in outline, the basal lobes pointing outward, so that the base appears truncate; may refer only to the base of a leaf with such lobes. Compare sagittate, which refers to basal lobes pointing backward.
A plant that has been transported voluntarily or involuntarily by humans in a territory which it could not have colonized by its own natural mechanisms of dissemination, or at least much more slowly.[34]
hemi-legume
A legume fruit in which the seed or seeds and one valve of the pod are dispersed as a unit. The valve catches the wind and blows away with the seeds, as in Acacia tenuifolia and Peltogyne paniculata.
A collection of preserved, usually pressed and dried, plant material used for identification and comparison; also a building in which such collections are stored.
A form of berry that occurs most familiarly in the genus Citrus. The fruit tends to be large for a berry, ranging from not much more than a centimeter in small fruited genera such as Murraya, to 15cm or more in some varieties of Citrus. The outer rind typically is thick and tough with many oil glands, while the carpels within are packed with juicy fibers.
The condition of a species having flowers with different style and stamen lengths, but with all the flowers of any one plant being identical. See distyly.
Protective outer covering of certain seeds, for example, the leafy outer covering of an ear of maize (corn), the leathery covering of the walnut, or the spiky covering of the chestnut.
Plant produced by the crossing of parents belonging to two different named groups, e.g. genera, species, varieties, subspecies, forma and so on; i.e. the progeny resulting within and between two different plants. An F1 hybrid is the primary product of such a cross. An F2 hybrid is a plant arising from a cross between two F1 hybrids (or from the self-pollination of an F1 hybrid).
hybrid formula
The names of the parents of a hybrid joined by a multiplication sign, e.g. Cytisus ardonoi × C. purgans.
Tube or cup-like structure in a flower that includes the bases of sepals, petals, and stamens, and may or may not be connected (adnate) to the ovary.
hyper-resupinate
In botany, describing leaves or flowers that are in the usual position but are borne on a petiole or pedicel that is twisted 360 degrees. The term is used to describe organs, such as orchid flowers, that are usually resupinate. Compare resupinate.
hypocarpium
Enlarged fleshy structure that forms below the fruit from the receptacle or hypanthium.
Of an embryo or seedling, the part of the plant axis below the cotyledon and node, but above the root. It marks the transition from root to stem development.
The intramarginal veins near the margins of this leaf are outlined in white.
Two of these three green Asteraceaeinvolucres encase unopened flower heads, and the third supports the open colorful head of emerging flowers. The imbricate phyllaries around the heads of this Malacothrix coulteri suggest the keeled scales of a snake, giving the plant its common name: "snake's head".
A name not abiding by the rules of the botanical Codes, e.g. later homonyms, cultivars that have been Latinised after 1 Jan 1959; cultivar names with more than 10 syllables or 30 letters; cultivar names that use confusing names of other plants, e.g. Camellia 'Rose'.
From the Latin for "tiled". Overlapping each other; of perianth parts, edges overlapping in the bud (the convoluted arrangement is a special form of imbrication). Dormant buds of many deciduous species are imbricately covered with protective cataphylls called bud scales. Compare with subimbricates meaning lightly overlapping
The production of offspring between closely related parents leading to a high degree of similarity; self-fertilization is the most intense form of inbreeding.
Of unknown taxonomic affinity; relationships obscure.
incised
Cut deeply and (usually) unevenly (a condition intermediate between toothed and lobed).
included
Enclosed, not protruding, e.g. stamens within the corolla.
incomplete flower
A flower which lacks one or more of its usual parts, such as carpels, sepals, petals, pistils, or stamens.
incurved
Bent or curved inward; of leafmargins, when curved toward the adaxial side.
ined.
An abbreviation of Latin inedita, an unpublished work. Used to indicate that a botanical name appeared only in a manuscript that was not published, so the name is invalid.
indefinite
variable in number, and as a rule numerous, e.g. more than twice as many stamens as petals or sepals, but no particular standard number of stamens. In another usage it is a synonym for the preferable term indeterminate, meaning the condition in which an inflorescence is not terminated by a flower, but continues growing until limited by physiological factors. Compare numerous. Contrast definite.
usually referring to a stem or inflorescence in which there is no particular terminal bud or meristem that stops growth and ends the extension of the stem, which continues until physiological factors stop the growth. Racemes of some Xanthorrhoeaceae, such as many Aloes, and of many Iridaceae, such as Watsonias, are indeterminate. Contrast determinate.
Native to the area, not introduced, and not necessarily confined to the region discussed or present throughout it (hardly distinct from ‘native' but usually applied to a smaller area). For example, the Cootamundra Wattle is native to Australia but indigenous to the Cootamundra region of southern New South Wales. Compare endemic.
a meristem located between the apex and the base of an organ
interjugary glands
in pinnate leaves, glands occurring along the leaf rachis between the pinnae (occurring below the single, and often slightly larger, gland at or just below the insertion of the pinnae). Compare jugary.
A structure surrounding or supporting, usually a head of flowers. In Asteraceae, it is the group of phyllaries (bracts) surrounding the inflorescence before opening, then supporting the cup-like receptacle on which the head of flowers sits. In Euphorbiaceae it is the cuplike structure that holds the nectar glands, nectar, and head of flowers, and sits above the bract-like cyathophyll structure. Involucres occur in Marchantiophyta, Cycads, fungi, and many other groups.
involute
Rolled inward, for example when the margins of a leaf are rolled toward the adaxial (usually upper) surface. Compare revolute.
Unusually dense stand of cypress knees around the parent tree
keel
adj.keeled
A prominent longitudinal ridge like the keel of a boat, e.g. the structure of the corolla formed by the fusion of the lower edge of the two abaxial anterior petals of flowers in the Fabaceae.
the highest generally employed category of the taxonomic hierarchy, above that of division (phylum). The Plant Kingdom includes vascular plants, bryophytes and green algae and is also known as the cladeViridiplantae.
Klausenfrucht
Klausen or Klausenfrucht (german) is a special type of fruits in Lamiaceae and Boraginaceae. A dry, dehiscent fruit formed from a superior ovary with axil or basal placentation, with an adherent calyx, from more than one carpel and usually breaking apart into 1-seeded units by separating each carpel by false septa. One unit is a half carpel, mostly there are four units, seeds. English terms are eremocarp, schizocarp, mericarp or nutlets.
abrupt bend in a root or stem, commonly at a node; a cypress knee, or pneumatophore, is a type of bend or knob in the root of some plants, especially conifers such as some of the Taxodioideae, that shows as a projection of the root above ground level or mud level.
Most Euphorbias are laticiferous and instantly exude latex when even mildly punctured.
A leaf scar on Juglans regia, showing the layer of corky protective tissue that remained after the leaf separated along the abscission zone. It also shows the leaf traces of the vascular bundles that broke off when the abscission zone failed. The axillary bud associated with the leaf shows just above the scar.
Of lobes – with ends irregularly divided into deeply divided, narrow, pointed segments; Of margins – deeply divided into pointed segments in an irregular manner.
lacuna
An empty space, hole, cavity, pit, depression, or discontinuity.
longer than broad, narrowly ovate, broadest in the lower half and tapering to the tip, like a lance or spear head; (sometimes, and incorrectly, used to mean narrowly elliptic).
lanuginose
covered in long hairs that cross and/or interweave with each other. More commonly the term lanate is used.[40]
Typically lenticular (lens-shaped) porous tissue in bark with large intercellular spaces that allows direct exchange of gases between the internal tissues and atmosphere through the bark.
A pod-like indehiscent fruit that develops constrictions between the segments and at maturity breaks into one-seeded segments instead of splitting open.
longicidal
(of anthers) Opening lengthwise by longitudinal slits. Compare poricidal.
A growth habit in which several woody stems arise separately from a lignotuber; a plant with such a growth habit, e.g. many Eucalyptus species; vegetation characterized by such plants.
Any shrub or small tree growing in salt or brackish water, usually characterized by pneumatophores; any tropical coastal vegetation characterized by such species.
Edible fruit and nuts produced by woody species of plants (e.g. acorns and beechmast) which is consumed on the ground by wildlife species and some domestic animals.
one segment of a fruit (a schizocarp) that splits at maturity into units derived from the individual carpels, or a carpel, usually 1-seeded, released by the break-up at maturity of a fruit formed from 2 or more joined carpels.
Moist, avoiding both extremes of drought and wet; pertaining to conditions of moderate moisture or water supply; applied to organisms (vegetation) occupying moist habitats.
A single individual that is free from other individuals, not united with them into a group. The term is usually used for pollen to distinguish single grains from tetrads or polyads.
(of vascular plants) Hermaphroditic, with all flowers bisexual, or with male and female reproductive structures in separate flowers but on the same plant, or of an inflorescence that has unisexual flowers of both sexes. Contrast dioecious.
Of a group of plants, a comprehensive treatise presenting an analysis and synthesis of taxonomic knowledge of that taxon; the fullest account possible (at the time) of a family, tribe or genus. It is generally worldwide in scope and evaluates all taxonomic treatments of that taxon including studies of its evolutionary relationships with other related taxa, and cytological, genetic, morphological, palaeobotanical and ecological studies. The term is often incorrectly applied to any systematic work devoted to a single taxon. Compare revision.
A cluster of fruits produced from more than one flower and appearing as a single fruit, often on a swollen axis, as with many species of the family Moraceae. Compare aggregate fruit.
The "vegetative" (nonreproductive) part of a fungus, mostly composed of aggregations of hyphae. It functions in substrate decomposition and absorption of nutrients.
A name that is either superfluous at its time of publication because the taxon to which it was applied already has a name, or the name has already been applied to another plant (a homonym).
nomen invalidum
A name that is not validly published, and technically is therefore not a botanical name. Abbreviation: nom. inval. See valid publication.
The naming of things; often restricted to the correct use of scientific names in taxonomy; a system that sets out provisions for the formation and use of names.
Of plants, containing harmful or unwholesome qualities. Applied in conjunction with 'weed' to specifically describe a plant which legislation deems harmful to the environment. Each state and territory in Australia has specific legislation governing noxious weeds.
The tissue of the ovule of a seed plant that surrounds the female gametophyte. It is enclosed by integuments and is not of epidermal origin.
numerous
Stamens are described as numerous when there are more than twice as many as sepals or petals, especially when there is no set number of them. Compare indefinite.
A prefix meaning "inversely"; usually the same shape as that described by the word stem, but attached by the narrower end. See obcordate, oblanceolate and obovate.
Loosely, the seed before fertilization; a structure in a seed plant within which one or more megaspores are formed (after fertilization it develops into a seed).
Carpobrotus and other prostrate plants growing on sand in Sicily, striking root and binding the soil as they grow
Floral stages of the protandrous species: Geranium incanum. The flower at first has intensely colored petals, and both androecium and gynoecium. After a day or so in bloom, it sheds the stamens and the color of the petals becomes somewhat paler.
In daisy florets, a tuft or ring of hairs or scales borne above the ovary and outside the corolla (representing the reduced calyx); a tuft of hairs on a fruit.
An organism living on or in a different organism, from which it derives nourishment. Some plant species are parasitic. Compare saprophyte and epiphyte.
Having a terminal lobe or leaflet, and on either side of it an axis curving outward and backward, bearing lobes or leaflets on the outer side of the curve.
With its base wrapped around the stem (so that the stem appears to pass through it), e.g. of leaves and bracts.
perforate
With many holes. Used to describe the texture of pollen exine, and also to indicate that tracheary elements have a perforation plate. See also fenestrate.
perforation plate
in a tracheary element, part of the cell wall that is perforated; present in vessel members but not in tracheids. Should not be confused with a pit.
The collective term for the calyx and corolla of a flower (generally used when the two are too similar to be easily distinguishable). Abbreviation: P; for instance, P 3+3 indicates the calyx and corolla each have 3 elements, i.e. 3 sepals + 3 petals.
Borne around the ovary, i.e. of perianth segments and stamens arising from a cup-like or tubular extension of receptacle (free from the ovary but extending above its base). Compare epigynous and hypogynous.
persistent
Remaining attached to the plant beyond the usual time of falling, for instance sepals not falling after flowering, flower parts remaining through maturity of fruit. Compare deciduous and caducous.
perule
adj.perulate
1. The scales covering a leaf or flower bud, or a reduced scale-like leaf surrounding the bud. Buds lacking perulae are referred to as "naked".
2.In Camellias the final bracts and sepals become indistinguishable and are called perules.
3.A kind of sac formed by the adherent bases of the two lateral sepals in certain orchids.
In a flower, one of the segments or divisions of the inner whorl of non-fertile parts surrounding the fertile organs, usually soft and conspicuously colored. Compare sepal, tepal.
A leaf with the blade much reduced or absent, and in which the petiole and or rachis perform the functions of the whole leaf, e.g. many acacias. Compare cladode.
phyllopodium
(in ferns) A short outgrowth of the stem on which the frond is borne and which remains attached to the rhizome after the frond has been shed.
phylloplane
the surface of a leaf, considered as a habitat for organisms.
A compound leaf with leaflets arranged on each side of a common petiole or axis; also applied to how the lateral veins are arranged in relation to the main vein.
a flower containing one or more pistils but no fertile stamens. Sometimes called a female flower. Contrast with staminate flower
pistillode
A sterile or rudimentary pistil such as may appear in a staminate flower.
pit
In tracheary elements, a section of the cell wall where the secondary wall is missing, and the primary wall is present. Pits generally occur in pairs and link two cells.
These rights, governed by Plant Breeder's Rights Acts give the plant breeder legal protection over the propagation of a cultivar, and the exclusive rights to produce and to sell it, including the right to license others to produce and sell plants and reproductive material of a registered, deliberately bred variety. Compare UPOV.
Pleated; folded back and forth longitudinally like a fan, such as the leaves of fan palm species. The concept often appears in specific names in forms such as Kumara plicatilis and Acacia plicata. Commonly such names are not correctly appropriate, but are applied to distichous structures rather than plicate.
-plinerved
(of leaves) A suffix indicating that the main nerves are lateral and arise from a point distinctly above the base of the leaf. Combined with a numerical prefix to form words like 3-plinerved, 5-plinerved, and so on. Such leaves are especially characteristic of the family Melastomataceae. See for example Dissotis.
plumose
Like a feather; with fine hairs branching from a main axis.
A vertical appendage, aerial at low tide, on the roots of some plants. Pneumatophore functions are unclear, but possibly related to gas exchange, or to root anchoring. Pneumatophores typically occur on mangrove roots, but some versions occur on species of conifers, such as some in the Taxodioideae.
pod
1.A legume, the fruit of a leguminous plant, a dry fruit of a single carpel, splitting along two sutures.
with more than two of the basic sets of chromosomes in the nucleus; any sporophyte with cells containing three or more complete sets of chromosomes. Various combinations of words or numbers with '-ploid' indicate the number of haploid sets of chromosomes, e.g. triploid = 3 sets, tetraploid = 4 sets, pentaploid = 5 sets, hexaploid = 6 sets, and so on.
polystemonous
having numerousstamens; the number of stamens being at least twice the number of sepals or petals, but not strictly three or four times that number.
A hard, pointed outgrowth from the surface of a plant (involving several layers of cells but not containing a vein); a sharp outgrowth from the bark, detachable without tearing wood. Compare thorn.
primary vein
The single vein or array of veins that is conspicuously larger than any others in a leaf. In pinnatevenation, the single primary vein can generally be found in the middle of the leaf; in palmate venation, several such veins radiate from a point at or near the base of the leaf.
In part. In nomenclature, used to denote that the preceding taxon includes more than one currently recognized entity, and that only one of those entities is being considered.
Having female sex organs which mature before the male ones, e.g. a flower shedding pollen after the stigma has ceased to be receptive. Compare protandrous.
proximal
Near the point of origin or attachment. Compare distal.
A prefix meaning "false, not genuine", e.g. a pseudo-bulb is a thickened, bulb-like internode in orchids, but not an actual bulb.
pseudobasifixed
(of an anther) Connected to the filament of the stamen by connective tissue which extends in a tube around the filament tip. See also basifixed and dorsifixed.
a swelling at either end of a petiole of a leaf or petiolule of a leaflet, e.g. in Fabaceae, that permits leaf movement.
punctate
(from Latin puncta= puncture or prick-mark) marked with an indefinite number of dots, or with similarly small items such as translucent glands or tiny hollows.
The stone of a drupe, consisting of the seed surrounded by the hardened endocarp.
pyriform
Pear-shaped; a term for solid shapes that are roughly conical in shape, broadest one end and narrowest at the other. As a rule the distal third of their length is the broadest, and they are narrowest near the proximal end, the base, where the stalk, if any, attaches.
An indeterminateinflorescence in which the main axis produces a series of flowers on lateral stalks, the oldest at the base and the youngest at the top. Compare spike. Also racemiform or racemoid - having the form of a raceme.
The axis of an inflorescence or a pinnate leaf; for example ferns; secondary rachis is the axis of a pinna in a bipinnate leaf distal to and including the lowermost pedicel attachment.
radial
With structures radiating from a central point as spokes on a wheel (e.g. the lateral spines of a cactus).
radiate
(of daisies, of a capitulum) With rayfloret surrounding disc florets.
Describing leaves or flowers that are in an inverted position because the petiole or pedicel, respectively, is twisted 180 degrees. compare: hyper-resupinate.
reticulate
forming a network (or reticulum), e.g. veins that join one another at more than one point.
Having a blunt (obtuse) and slightly notched apex.
revision
an account of a particular plant group, like an abbreviated or simplified monograph. Sometimes confined to the plants of a particular region. Similar to a monograph in clearly distinguishing the taxa and providing a means for their identification. Compare monograph.
revolute
rolled under (downward or backward), for example when the edges of leaves are rolled under toward the midrib. Compare involute.
a unit of a plant's axial system which is usually underground, does not bear leaves, tends to grow downward, and is typically derived from the radicle of the embryo.
when parts are not whorled or opposite but appear so, due to the contractions of internodes, e.g. the petals in a double rose or a basal cluster of leaves (usually close to the ground) in some plants.
a plant that colonises or occupies disturbed waste ground. See also weed.
rudiment
In the structure of a plant, an item that is at best hardly functional, either because it is immature and has not yet completed its development (such as a leaf still incompletely formed inside a bud), or because its role in the organism's morphology cannot be completed and therefore is futile (such as the leaf rudiment at the tip of a phyllode, that will be shed while immature, because the leaf function will be taken over by the phyllode). Compare cataphyll and vestige.
rudimentary
Being of the nature of a rudiment; at most barely functional because incompletely developed; begun, but far from completed, either temporarily or permanently. Compare vestigial.
rugose
Wrinkled, either covered with wrinkles, or crumpled like a wrinkled leaf, either as a stiffening structure, or in response to disease or insect damage.
Trametes versicolor, the turkey tail fungus, is a saprotroph that consumes dead wood in forests. Its common name comes from the conspicuously patterned brackets, but the main body of the saprotroph consists of the largely invisible mycelium that penetrates the dead wood and digests it.
Strawberry plants reproduce mainly by sarments, stolons such as these, often called runners; at their nodes the sarments put up tufts of leaves and strike root if there is any good soil beneath.
Amaryllis belladonna in flower, an example of a leafless scape emerging directly from the underground bulb before the seasonal leaves
Involucral bracts of Syncarpha species are as scarious as tissue paper, but look like live petals for years, so they are known as "Everlastings" and valued for dried arrangements.
Spadix of Amorphophallus maximus within its spathe. The female flowers are around the bottom of the spadix, the male flowers above, and the sterile top part is the major source of pollinator attractants.
Shaped like the head of an arrow; narrow and pointed but gradually enlarged at the base into two straight lobes directed downward; may refer only to the base of a leaf with such lobes. Compare hastate.
salverform
Shaped like a salver - Trumpet-shaped; having a long, slender tube and a flat, abruptly expanded limb
A plant, or loosely speaking, a fungus or similar organism, deriving its nourishment from decaying organic matter such as dead wood or humus, and usually lacking chlorophyll. Compare parasite, saprotroph, and epiphyte.
The category of supplementary taxa intermediate in rank between subgenus and series. It is a singular noun always written with a capital initial letter, in combination with the generic name.
secund
Having all the parts grouped on one side or turned to one side (applied especially to inflorescences).
A ripened ovule, consisting of a protective coat enclosing an embryo and food reserves; a propagating organ formed in the sexual reproductive cycle of gymnosperms and angiosperms (together, the seed plants).
A descriptive term for stigmas that, in response to touch, close the two lobes of the stigma together, ending the receptivity of the stigma, at least for the time that the lobes are closed together. Mimulus is perhaps the best-known example.
In a flower, one of the segments or divisions of the outer whorl of non-fertile parts surrounding the fertile organs; usually green. Compare petal, tepal.
The category of supplementary taxa intermediate in rank between section and species. It is often used as a plural adjective, as in "Primula subgenus Primula sect. Primula series Acaules".
serrate
Toothed with asymmetrical teeth pointing forward; like the cutting edge of a saw.
A dry, dehiscent fruit (in contrast to a silicula, more than twice as long as wide) formed from a superior ovary of two carpels, with two parietal placentas and divided into two loculi by a 'false' septum.
The science of forestry and the cultivation of woodlands for commercial purposes and wildlife conservation.
simple
Undivided or unsegmented, e.g. a leaf not divided into leaflets (note, however, that a simple leaf may still be entire, toothed or lobed) or an unbranched hair or inflorescence.
sinuate
Having deep, wave-like depressions along the margins, but more or less flat. Compare undulate.
A spicate (spike-like) inflorescence with the flowers crowded densely, even solidly, around a stout, often succulentaxis. Particularly typical of the family Araceae
A group, or populations of individuals, sharing common features and/or ancestry, generally the smallest group that can be readily and consistently recognized; often, a group of individuals capable of interbreeding and producing fertile offspring. The basic unit of classification, the category of taxa of the lowest principal rank in the nomenclatural hierarchy. Strict assignment to a species is not always possible, as it is subject to particular contexts, and the species concept under consideration.
Follows the name of the genus, and is the second word of a botanical binomial. The generic name and specific epithet together constitute the name of a species, i.e. the specific epithet is not the species name.
speirochoric
Unintentional introduction by seeds.[46] Compare agochoric.
A stiff, sharp structure formed by the modification of a plant organ that contains vascular tissue, e.g. a lateral branch or a stipule; includes thorns.
A cup-like structure in fungi such as Nidulariaceae and in cryptogams such as some mosses. The cups function in spore dispersal, in which the energy of raindrops falling into the cup causes the water to splash outward carrying the spores.[47]
A naturally occurring variant of a species, not usually present in a population or group of plants; a plant that has spontaneously mutated so that it differs from its parent plant.
spreading
Extending horizontally, e.g. in branches. Standing out at right angles to an axis, e.g. in leaves or hairs.
Generally a small stalk or stalk-like structure. The stalk of a frond of a fern; the stalk supporting the pileus of a mushroom; the stalk of a seaweed such as a kelp; the stalk-like support of a gynaecium or a carpel
stipella
Also stipel; pl.stipellae
One of two small secondary stipules at the base of leaflets in some species.
A category of supplementary taxa intermediate between genus and section. The name of a subgenus is a singular noun, always has a capital initial letter and is used in combination with the generic name, e.g. Primula subgenus Primula.
A taxonomic category within a species, usually used for geographically isolated or morphologically distinct populations of the same species. Its taxonomic rank occurs between species and variety.
A shoot of more or less subterranean origin; an erect shoot originating from a bud on a root or a rhizome, sometimes at some distance from the stem of the plant.
A mode of growth in which the main axis is repeatedly terminated and replaced with a lateral branch. Examples occur in the family Combretaceae, including the genera Terminalia and Combretum. Compare monopodial.
A fused aggregate of sporangia, e.g. in the trilocular sporangia of the whisk fern Psilotum.
synanthous
A type of growth in which new leaves and flowers appear and die back at the same time. See also hysteranthous and proteranthous.
synaptospermy
The dispersal of diaspores as units, where each bears more than one seed, for example where each diaspore comprises an entire inflorescence, as in Brunsvigia or multi-seeded fruit as in Tribulus zeyheri. Ephemeral synaptospermy is the term for when the diaspores split into units containing fewer or single seeds each, as in most tumbleweeds. True synaptospermy is when the diaspore generally remains entire until germination, as commonly happens in species of Grielum.
One of the usually two synangia in which pollen is produced in flowering plants. It consists of two fused sporangia known as pollen sacs. The wall between the pollen sacs disintegrates before dehiscence, which is usually by a common slit.
In non-filamentous plants, any hair-like outgrowth from the epidermis, e.g. a hair or bristle; sometimes restricted to unbranched epidermal outgrowths.
trichotomous
3-forked or branched into three. Compare dichotomous.
The second word in the two-part scientific name of an organism. Compare specific epithet.
trophophyll
A vegetative, nutrient-producing leaf or microphyll whose primary function is photosynthesis. It is not specialized or modified for some other function. Compare sporophyll.
Any of many types of specialized vegetative underground storage organs. They accumulate food, water, or in protection from death by fire, drought, or other hard times. Tubers generally are well differentiated from other plant organs; for example, informally a carrot is not generally regarded as a tuber, but simply a swollen root. In this they differ from the tuber of a sweet potato, which has no special root-like function. Similarly, corms are not generally regarded as tubers, even though they are underground storage stems. Tubers store food for the plant, and also have important roles in vegetative reproduction. They generally are of two main types: stem tubers form by the swelling of an underground stem growing from a root, or from structures such as underground stolons. Stem tubers generally produce propagative buds at their stem nodes, forming a seasonal perennating organ, e.g. a potato. The main other class is the root tuber, also called tuberoid. They differ from stem tubers in features such as that, like any normal root, they do not form nodes.
An item (usually an herbarium specimen) to which the name of a taxon is permanently attached, i.e. a designated representative of a plant name. Important in determining the priority of names available for a particular taxon.
Terete raceme of Kniphofia shown together with a cross section of a peduncle. A:Inflorescence;B: Terete peduncle;C: Cross section of a terete peduncle
Gymnosporia buxifolia has true thorns, that is, modified branches. In some species such branches are complete with buds and leaves.
Sweet potatotubers exposed, showing them to be root tubers. Morphologically, they differ from stem tubers of potatoes, for example, in that root tubers do not have nodes that bear buds. The root tubers of some species of plants, however, can produce adventitious buds for vegetative reproduction.
Corms of Crocosmia bear typical tunics formed of cataphylls growing from the nodes of the corm. The illustration shows still-living cataphylls as white tissue, whereas the functional, hard, resistant tunic is brown.
Turbinate (spinning top-shaped) roots of sugar beet
Haworthia lockwoodii, with its leaves turgid and green after seasonal rains, store water against the coming dry period.
A racemose inflorescence in which all the individual flower stalks arise in a cluster at the top of the peduncle and are of about equal length; in a simple umbel, each stalk is unbranched and bears only one flower. A cymose umbel looks similar to an ordinary umbel but its flowers open centrifugally.
umbo
A rounded elevation, such as in the middle of the top of an umbrella or mushroom; a central boss or protuberance, such as on the scale of a cone.
umbonate
Having an umbo, with a conical or blunt projection arising from a flatter surface, as on the top of a mushroom or in the scale of a pine cone.
Shaped like an urn or pitcher, with a swollen middle and narrowing top. Examples include the pitchers of many species of the pitcher plant genera Sarracenia and Nepenthes.
usu.
An abbreviation of usually. Compare s.t. and oft..
utricle
1.A small bladder; a membranous bladder-like sac from the ovary wall, thin pericarp, becomes more or less bladdery or inflated at maturity enclosing an ovary or fruit.
2.In sedges, a fruit in which the fruit is loosely encloses from a modified tubular bract, see perigynium.
A resin canal coinciding with a longitudinal groove in the seeds of Asteraceae. A longitudinal cavity in the cortex of the stems of Equisetum, coinciding with a groove in the stem surface.
A bundle of vascular tissue in the primary stems of vascular plants, consisting of specialized conducting cells for the transport of water (xylem) and assimilate (phloem).
From Latin venter, meaning "belly". The opposite of dorsal. Partly because the term originally referred to animals rather than plants, usage in botany is arbitrary according to context and source. In general "ventral" refers to "the belly or lower part", but in botanical usage such concepts are not always clearly defined and may be contradictory. For example:
facing toward the axis (adaxial) in referring to a lateral organ of an erect plant
facing toward the substrate in any part of an erect plant, for example the lower surface of a more or less horizontal leaf (abaxial)
facing toward the substrate in a prostrate or climbing plant.
Arranged in one or more whorls, i.e. several similar parts arranged at the same point of the axis, e.g. leaf arrangement. Compare pseudoverticillate (appearing whorled or verticillate but not actually so).
1.Any plant growing where it is not wanted; commonly associated with disrupted habitats. See also ruderal.
2.An unwanted plant which grows among agricultural crops.
3.A naturalised, exotic, or ecologically "out-of-balance" indigenous species outside of the agricultural or garden context, which, as a result of invasion, adversely affects the survival or regeneration of indigenous species in natural or partly natural vegetation communities.[54]
wild
Originating from a known wild or purely natural habitat (wilderness).
A ring of organs borne at the same level on an axis (e.g. leaves, bracts, or floral parts).
wing
1.A membranous expansion of a fruit or seed which aids in dispersal, for instance on pine seeds.
2.A thin flange of tissue extending beyond the normal outline of a structure, e.g. on the column of some orchids, on stems, on petioles.
3.One of the two lateral petals of a flower of subfamily Faboideae of family Fabaceae, located between the adaxial standard (banner) petal and the two abaxial keel petals.
A plant with structural features (e.g. hard or succulent leaves) or functional adaptations that prevent water loss by evaporation; usually associated with arid habitats, but not necessarily drought-tolerant. Compare xerophyte.
A plant generally living in a dry habitat, typically showing xeromorphic or succulent adaptation; a plant able to tolerate long periods of drought. Compare xeromorph.
Bilaterally symmetrical; symmetrical about one vertical plane only; applies to flowers in which the perianth segments within each whorl vary in size and shape. Contrast actinomorphic and irregular.
Harris, James G.; Harris, Melinda Woolf (2001). Plant Identification Terminology: an Illustrated Glossary (2nded.). Spring Lake, Utah, US: Spring Lake Publishing. ISBN0-9640221-6-8.