Cypripedioideae is a

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...

of orchids commonly known as lady's slipper orchids, lady slipper orchids or slipper orchids. Cypripedioideae includes the

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

'' Cypripedium, Mexipedium, Paphiopedilum,

Phragmipedium ''Phragmipedium'' is a genus of the Orchid family (Orchidaceae) (Subfamily Cypripedioideae) and the only genus comprised in the tribe Phragmipedieae and subtribe Phragmipediinae. The name of the genus is derived from the Greek ''phragma'', which ...

'' and ''

Selenipedium ''Selenipedium'' is a genus of the Orchid family (''Orchidaceae'') (Subfamily ''Cypripedioideae''). The genus has been given its own tribe, Selenipedieae, and subtribe, Selenipediinae.Pridgeon, A.M.; Cribb, P.J.; Chase, M.W. & F. N. Rasmussen (19 ...

''. They are characterised by the slipper-shaped pouches (modified labella) of the flowers – the pouch traps insects so they are forced to climb up past the

staminode In botany, a staminode is an often rudimentary, sterile or abortive stamen, which means that it does not produce pollen.Jackson, Benjamin, Daydon; ''A Glossary of Botanic Terms with their Derivation and Accent''; Published by Gerald Duckworth & Co. ...

, behind which they collect or deposit pollinia, thus fertilizing the flower. There are approximately 165 species in the subfamily.

Description

All representatives of the Cypripedioideae are perennial, herbaceous plants. The fleshy roots sometimes possess a veil. The leaves are arranged spirally or in two rows, the shoot is slender or compressed. In the bud, the leaves are rolled and the leaf blade is plikat (folded) or the leaves are folded in the bud, smooth and leathery. There is no dividing tissue between leaf and shoot. The inflorescence of the Cypripedioideae are terminal and mostly unbranched. The flowers are spiral or in two lines on the shoot, they are resupinated. The petals are in two threefold circles, with mostly two petals of the outer circle are completely fused. The labellum forms a sac-like structure. The ovary is under constant and one-chambered or three-chambered. Two fertile stamens, a staminode and style are fused into a complex structure. The stylus is short and thick, the stigma is large and convex, the central lobe of the stigma is larger than the two lateral ones. The two lateral stamens are fertile, the pollen grains are glued together to form a paste or formed into connected pollinia in some ''

'' species. The middle, barren stamen is shield-shaped widened. The fruits are mostly capsule fruits, with Selenipedium they are berry-like. They contain numerous flattened seeds, about a millimeter long and 0.1 millimeters wide. In contrast, the seeds of Selenipedium are lens-shaped and have a hard seed coat. Chromosome numbers vary within the subfamily over a wide range from 2n=20 in '' Cypripedium'' to 26 to 44 chromosomes in '' Paphiopedilum''. The chromosomes are quite large. The species in this subfamily form trap flowers in which insect access to the saclike lip from the front is quite easy. The inside is designed in such a way that the insects climb out of the flower past the stigma and the stamens and thereby pollinate the flower.

Distribution

The species in the subfamily Cypripedioideae are found in northern South America and Central America (Mexipedium, Phragmipedium, Selenipedium), circumboreal in North America, Europe, Africa (Algeria) and in northern Asia (Cypripedium) as well as in subtropical and tropical Southeast Asia (Paphiopedilum). They do not occur in Australia and Africa. The spread could have started from a center of origin in Central America.

Taxonomy

Unlike most other orchids, slipper orchids have two fertile

anther The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

s — they are "diandrous". For that reason, experts have debated whether this

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

should be classified within the orchid family ( Orchidaceae), or whether they should compose a separate family altogether called Cypripediaceae. Around the year 2000, molecular phylogenetics and DNA sampling have come to play an increasingly important role in classification. This has led to the conclusion that recognition of a distinct family Cypripediaceae would be inappropriate. The subfamily Cypripedioideae is

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

and consists of five genera: :* '' Cypripedium'', found across much of

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

, as well as in parts of Europe (one species), Africa (only in Algeria has been discovered in 2019) and Asia. The state flower of Minnesota is the showy lady's slipper (''

Cypripedium reginae ''Cypripedium reginae'', known as the showy lady's slipper, pink-and-white lady's-slipper, or the queen's lady's-slipper, is a rare lady's-slipper orchid native to northern North America. Although never common, this plant has vanished from much o ...

''); the pink lady's slipper (''

Cypripedium acaule ''Cypripedium acaule'' is a species of flowering plant in the orchid family Orchidaceae. It is commonly referred to as the pink lady's slipper or moccasin flower. The specific epithet ''acaule'' means "lacking an obvious stem", a reference to it ...

'') is the official flower of the

Canadian province Within the geographical areas of Canada, the ten provinces and three territories are sub-national administrative divisions under the jurisdiction of the Canadian Constitution. In the 1867 Canadian Confederation, three provinces of British North ...

of Prince Edward Island. :* '' Mexipedium'', a monotypic genus, consisting of a single species that was found in a single locality in Oaxaca, Mexico. :* '' Paphiopedilum'', found in the tropical forests of southeast Asia reaching as far north as southern

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

. ''Paphiopedilum'' is quite easy to cultivate and therefore is popular among orchid enthusiasts. In fact, over-collection of this genus has been so extensive that many species are now sub-viable in their natural habitats. :* ''

'', found across northern South and Central America, is also easy to cultivate as it requires lower temperatures than ''Paphiopedilum'', eliminating the need for a

greenhouse A greenhouse (also called a glasshouse, or, if with sufficient heating, a hothouse) is a structure with walls and roof made chiefly of Transparent ceramics, transparent material, such as glass, in which plants requiring regulated climatic condit ...

in many areas. :* ''

'', found in

Central Central is an adjective usually referring to being in the center of some place or (mathematical) object. Central may also refer to: Directions and generalised locations * Central Africa, a region in the centre of Africa continent, also known as ...

and South America.

Intergeneric hybrids

Hybrids between the genera in this subfamily are placed in the following nothogenera:Alphabetical One-Table List of Genera and Intergeneric Hybrids
Royal Horticultural Society, 2017. * × ''Cyphiopedilum'' (''Cphd.'') = ''Cypripedium'' × ''Paphiopedilum'' * × ''Cyphragmipedium'' (''Cgd.'') = ''Cypripedium'' × ''Phragmipedium'' * × ''Phragmipaphium'' (''Phrphm.'') = ''Paphiopedilum'' × ''Phragmipedium'' Hybrids with genera outside of the subfamily are not known as of 2017.

References

External links

* *
The Slipper Orchid Alliance

SlipperOrchids.info
{{Taxonbar, from=Q132226 Asparagales subfamilies Provincial symbols of Prince Edward Island