Apostasioideae is one of the five subfamilies recognised 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 ...

. Only two

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 ...

, '' Neuwiedia'' and ''Apostasia'', and 15

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

, are recognised within the Apostasioideae in contrast to the other orchid subfamilies which are highly species rich. The Apostasioideae are generally considered a basal lineage within the orchids based on molecular data and flower structure. All other orchid subfamilies with the exception of the

Cypripedioideae Cypripedioideae is a subfamily of orchids commonly known as lady's slipper orchids, lady slipper orchids or slipper orchids. Cypripedioideae includes the genera ''Cypripedium, Mexipedium, Paphiopedilum, Phragmipedium'' and ''Selenipedium''. They ...

are

monandrous In botanical terms, monandrous simply means to have a single stamen. In orchids A distinction between monandrous and other flowers is particularly relevant in the classification of orchids. The monandrous orchids form a clade consisting of the s ...

(possessing a single

stamen 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 filame ...

), however Apostasioid orchids have 3 stamens. As with all basal or 'primitive' groups,

extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Extant taxon, a taxon which is not extinct, ...

species within Apostasioideae do not represent direct ancestors of the other subfamilies, they simply share the same common ancestor. However, by having followed a separate evolutionary pathway from the other orchids extant Apostasioid orchids may allow biologists to make inferences about features present in that common ancestor.

References

Bibliography

* Pridgeon, A.M.; Cribb, P.J.; Chase, M.W. & F. N. Rasmussen (1999): Genera Orchidacearum Vol.1, Oxford U. Press. {{Taxonbar, from=Q133013 Asparagales subfamilies