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 ...

orchid Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Along with the Asteraceae, they are one of the two largest families of flowering ...

s 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 ''Cypripedium'' is a genus of 58 species and nothospecies of hardy Orchidaceae, 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 He ...

Mexipedium ''Mexipedium'' is a monotypic genus of the Orchid family Orchidaceae, subfamily Cypripedioideae, consisting of only one species, ''Mexipedium xerophyticum''. It is also the single genus of tribe Mexipedieae and subtribe Mexipediinae. Taxonomy an ...

Paphiopedilum ''Paphiopedilum'', often called the Venus slipper, is a genus of the lady slipper orchid subfamily ''Cypripedioideae'' of the flowering plant family Orchidaceae. The genus comprises some 80 accepted taxa including several natural hybrids. The ge ...

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 (1 ...

''. They are characterised by the slipper-shaped pouches (modified labella) of the

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

s – 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 A pollinium (plural pollinia) is a coherent mass of pollen grains in a plant that are the product of only one anther, but are transferred, during pollination, as a single unit. This is regularly seen in plants such as orchids and many species of mil ...

, 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 ''

'' to 26 to 44 chromosomes in ''

''. 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 Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Along with the Asteraceae, they are one of the two largest families of flowering ...

), or whether they should compose a separate family altogether called Cypripediaceae. Around the year 2000,

molecular phylogenetics Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

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: :* ''

'', 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 Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

(one species),

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

(only in

Algeria ) , image_map = Algeria (centered orthographic projection).svg , map_caption = , image_map2 = , capital = Algiers , coordinates = , largest_city = capital , relig ...

has been discovered in 2019) and

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

. The state flower of

Minnesota Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the 22nd most populous, with over 5.75 million residents. Minnesota is home to western prairies, now given over to ...

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 ...

Prince Edward Island Prince Edward Island (PEI; ) is one of the thirteen Provinces and territories of Canada, provinces and territories of Canada. It is the smallest province in terms of land area and population, but the most densely populated. The island has seve ...

. :* ''

'', a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

genus, consisting of a single species that was found in a single locality in Oaxaca, Mexico. :* ''

'', found in the tropical forests of

southeast Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consistin ...

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

temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer. Thermometers are calibrated in various temperature scales that historically have relied o ...

s 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 South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

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