Cypripedium

Cypripedium is a genus of 58 species and nothospecies of hardy orchids; it is one of five genera that together compose the subfamily of lady's slipper orchids (Cypripedioideae). They are widespread across much of the Northern Hemisphere, including most of Europe and Africa (Algeria^[2]) (one species), Russia, China, Central Asia, Canada the United States, Mexico, and Central America.^[1][3][4][5] They are most commonly known as slipper orchids, lady's slipper orchids, or ladyslippers; other common names include moccasin flower, camel's foot, squirrel foot, steeple cap, Venus' shoes, and whippoorwill shoe. An abbreviation used in trade journals is "Cyp." The genus name is derived from Ancient Greek Κύπρις (Kúpris), an early reference in Greek myth to Aphrodite, and πέδιλον (pédilon), meaning "sandal".^[6]

Cypripedium
Showy lady's slipper (Cypripedium reginae)
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Monocots
Order:	Asparagales
Family:	Orchidaceae
Subfamily:	Cypripedioideae
Genus:	Cypripedium L., 1753
Type species
Cypripedium calceolus L., 1753
Synonyms[1]
Arietinum Beck Calceolaria Heist. ex Fabr., not to be confused with Calceolaria L. Calceolus Mill. Ciripedium Zumagl. Criogenes Salisb. Criosanthes Raf. Cypripedilon St.-Lag. in A.Cariot Fissipes Small Hypodema Rchb. Sacodon Raf. Schizopedium Salisb.

Cypripedium, trapping a bee so it goes through a narrow passage where it picks up the pollinia to perform pollination.

Most of Cypripedium grow in temperate and subtropical climates, but some species grow in the tundra in Alaska and Siberia, which is an unusually cold habitat for orchids. Other species occur well into tropical areas such as Honduras and Myanmar.^[1]

Some of the northern species can withstand extreme cold, growing under the snow and blooming when the snow melts. But, in the wild, some have become rare and close to extinction, due to an ever shrinking natural habitat and over-collection, people prizing the flowers for their beauty. Several species are legally protected in some regions. In the late 20th century, only a single known plant of Cypripedium calceolus survived in Britain.

Characteristics

The Cypripedium are terrestrial and, as with most terrestrial orchids, the rhizome is short and robust, growing in the uppermost soil layer. The rhizome grows annually with a growth bud at one end and dies off at the other end. The stem grows from the bud at the tip of the rhizome. Most slipper orchids have an elongate erect stem, with leaves growing along its length. But the mocassin flower or pink lady's slipper (Cypripedium acaule) has a short underground stem with leaves springing from the soil. The often hairy leaves can vary from ovate to elliptic or lanceolate, folded (plicate) along their length. The stems lack pseudobulbs.

The inflorescence is racemose. It can carry one to twelve flowers, as in Cypripedium californicum. But most species have one to three flowers. There are three sepals, with, in most species, the two lateral ones more or less fused. The flower has three acute petals with the third a striking slipper-shaped lip, which is lowermost. The sepals and the petals are usually similarly colored, with the lip in a different color. But variations on this theme occur. The aspect of the lip of different species can vary a great deal. As with all orchids, it is specially constructed to attract pollinators, which it traps temporarily. The flowers show a column with a unique shield-like staminode. The ovary is 3-locular (with three chambers).

Taxonomy

Comparison between a DNA-analysis and the morphological characteristics in this genus has shown that there is a high degree of divergence between the two, probably due to long periods of isolation or extinction of intermediate forms. The Eurasian species with yellow or red flowers form a distinct group from the North American species with yellow flowers. The Mexican Pelican Orchid (Cypripedium irapeanum) and the California lady's slipper (Cypripedium californicum) are probably the first diverging line. They share several similarities with their sister group Selenipedium.

Species and natural hybrids

There are 58 currently recognized species and nothospecies (naturally occurring hybrids) recognized in this genus, as of May 2014:^[1]

Subgenus Cypripedium

Section	Image	Name	Distribution
Acaulia		Cypripedium acaule – Mocassin flower, Pink lady's slipper, Two-leaved lady's slipper	C. and E. Canada, NC & E USA
Arietinum		Cypripedium arietinum – Ram's-head lady's slipper	C & E Canada, NC & NE USA
		Cypripedium plectrochilum	N Myanmar to SC China
Bifolia		Cypripedium guttatum – Spotted lady's slipper	European Russia to Korea, Alaska to Yukon
		Cypripedium yatabeanum	Russian Far East to N & NC Japan, Aleutian Islands to SW Alaska
Cypripedium		Cypripedium calceolus – Yellow lady's slipper	Europe to Japan, Algeria
		Cypripedium candidum – Small white lady slipper	SE Canada, NC & E USA
		Cypripedium cordigerum – Heart-Lip lady's slipper	N Pakistan to Himalaya, S Tibet
		Cypripedium farreri	China
		Cypripedium fasciolatum	China
		Cypripedium henryi – Henry's lady's slipper	C China
		Cypripedium kentuckiense – Kentucky lady's slipper, Southern lady's slipper	C & E USA
		Cypripedium montanum – Large lady's slipper, Mountain lady's slipper, White lady's slipper, Moccasin flower	Alaska to California
		Cypripedium parviflorum Salisb. – (Greater) yellow lady's slipper, moccasin flower, or hairy yellow ladyslipper	Canada, E USA
		Cypripedium segawai	EC Taiwan
		Cypripedium shanxiense	China to N Japan
Eniantopedilum		Cypripedium fasciculatum – Brownie lady's slipper, Clustered lady's slipper	W USA
Flabellinervia		Cypripedium japonicum – Japan lady's slipper	China, Korea, Japan
		Cypripedium formosanum – Formosa lady's slipper	C Taiwan
Macrantha		Cypripedium calcicola	China
		Cypripedium franchetii – Franchet's lady's slipper	C & SC China
		Cypripedium himalaicum	SE Tibet to Himalaya
		Cypripedium ludlowii	SE Tibet
		Cypripedium macranthos – Large-flowered lady's slipper	E Belarus to temperate E Asia
		Cypripedium taibaiense	China
		Cypripedium taiwanalpinum	Taiwan
		Cypripedium tibeticum	Sikkim to C China
		Cypripedium yunnanense	SE Tibet, China
Retinervia		Cypripedium elegans	E Nepal to China
		Cypripedium debile – Frail lady's slipper	Japan, Taiwan, China
		Cypripedium palangshanense	China
Sinopedilum		Cypripedium bardolphianum	China
		Cypripedium forrestii	China
		Cypripedium micranthum	China
Trigonopedia		Cypripedium daweishanense (S.C.Chen & Z.J.Liu) S.C.Chen & Z.J.Liu (2005)	Yunnan, China South-Central
		Cypripedium fargesii	China
		Cypripedium lentiginosum	China
		Cypripedium lichiangense S.C.Chen & P.J.Cribb	China (SW Sichuan, NW Yunnan), NE Myanmar
		Cypripedium malipoense S.C.Chen & Z.J.Liu	Yunnan, China South-Central
		Cypripedium margaritaceum – Pearl-white lady's slipper	China
		Cypripedium sichuanense	China
		Cypripedium wumengense	China (NE. Yunnan)

Subgenus Irapeana

Section	Image	Name	Distribution
Irapeana		Cypripedium californicum – California lady's slipper	Oregon, N. California
		Cypripedium conzattianum	Mexico (Colima)
		Cypripedium gomezianum	Mexico (Colima)
		Cypripedium luzmarianum	Mexico (Jalisco, Michoacán)
		Cypripedium molle	Mexico
		Cypripedium dickinsonianum	Mexico (S Chiapas) to Guatemala
		Cypripedium irapeanum – Pelican Orchid, Irapeao lady's slipper	Mexico to Honduras
		Cypripedium susanae	Mexico (Nayarit)
Obtusipetala		Cypripedium flavum – Yellow lady's slipper	SE Tibet, SC China
		Cypripedium passerinum – Franklyn's lady's slipper, small white Northern lady's slipper, sparrow's egg lady's slipper	Alaska to Canada, Montana
		Cypripedium reginae Walter – Large white lady's slipper, Queen's lady's slipper, showy lady's slipper	C & E Canada, E. USA
Subtropica		Cypripedium subtropicum	SE. Tibet
		Cypripedium wardii	SE. Tibet, China

Natural Hybrids

Image	Scientific name	Common Name	Distribution
	Cypripedium × alaskanum	C. guttatum × C. yatabeanum	Alaska
	Cypripedium × andrewsii	C. candidum × C. parviflorum var. pubescens	E Canada, NC & NE USA
	Cypripedium × catherinae	C. macranthon × C. shanxiense	Russian Far East
	Cypripedium × columbianum	C. montanum × C. parviflorum var. pubescens	W Canada, NW USA
	Cypripedium x herae	C.parviflorum x C.reginae	Manitoba, Canada
	Cypripedium × ventricosum	C. calceolus × C. macranthos	Russia to Korea
	Cypripedium × wenqingiae	C. farreri × C. tibeticum	China

Uses

The genus has a long history of use, dating back 2,500 years to the Far East, where they were used medicinally.

Conservation

Several orchid species thought to be extinct in the United Kingdom including one native species in this genus have been found in habitat and are currently the subject of aggressive conservation efforts to protect and restore these showy plants to their native ranges.^[7]

Awards

The following have received the Royal Horticultural Society's Award of Garden Merit:-

• Cypripedium formosanum^[8]
• Cypripedium Hank Small gx^[9]
• Cypripedium Michael gx^[10]
• Cypripedium reginae^[11]
• Cypripedium Sabine gx^[12]