Apostasia orchid

Taxobox
name = "Apostasia"

---

image_caption = "Apostasia wallichii", Illustration.
regnum = Plantae
divisio = Magnoliophyta
classis = Liliopsida
ordo = Asparagales
familia = Orchidaceae
subfamilia = Apostasioideae
genus = "Apostasia"
genus_authority = Blume, 1825
subdivision_ranks = Species
subdivision = See text.

"Apostasia" is a genus of primitive orchids (family Orchidaceae), comprising 7 terrestrial species.

The genus is distributed in humid areas of the Himalayan region, India, Sri Lanka, New Guinea, and North Australia.

The species of "Apostasia" produce an erect inflorescence with up to six lateral branches, arising from the main, elongated root. Their warty tubercles are swollen and stalked. They lack a velamen.

They bear up to 30 white or yellow flowers. The flowers of Apostasia species are not resupinate (= turned upside down), as in the other orchids.

Like "Neuwiedia" with 3 fertile stamens, the other genus of the same subfamily, "Apostasia" is noted for having 2 fertile, abaxial stamens instead of one like other orchids. The possession of 2-3 abaxial anthers is autapomorphous (= a derived characteristic unique to a taxon) in the Apostasioideae. "Apostasia nuda", "Apostasia elliptica" and "Apostasia latifolia" lack a staminode. This loss of a staminode is an apomorphy (= derived characteristic). The other species are characterized by a staminode that is homologous to the only stamen of monandrous orchids. This presence of a staminode defines an ancestral trait (= plesiomorphic).

Because of that primitive feature, some authority did not consider "Apostasia" as real orchids. Nevertheless the difference between these genera and outgroups in cladistic analysis is larger than with the rest of the orchids. They are therefore included within the orchid family.

The genera "Adactylus" Rolfe and "Mesodactylis" Wall., "Neumayera" Rchb.f and "Niemeyera" F.Muell. have been brought into synonymy with "Apostasia".

Species

* "Apostasia elliptica" J.J.Sm., 1920.
* "Apostasia latifolia" Rolfe, 1889.
* "Apostasia nuda" R.Br. in N.Wallich, 1830.
* "Apostasia odorata" Blume, 1825.
* "Apostasia parvula" Schltr., 1906.
* "Apostasia ramifera" S.C.Chen & K.Y.Lang, 1986.
* "Apostasia wallichii" R.Br. in N.Wallich, 1830.

References

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*
*Pridgeon, A.M.; Cribb, P.J.; Chase, M.W. & F. N. Rasmussen (1999): Genera Orchidacearum Vol.1, Oxford U. Press. ISBN 0-19-850513-2