Envoy at 07:03, 26 June 2007

2007-06-26T07:03:46Z

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{{Taxobox
| color = lightgreen
| name = ''Apostasia''
| regnum = [[Plant]]ae
| divisio = [[Flowering plant|Magnoliophyta]]
| classis = [[Monocotyledon|Liliopsida]]
| ordo = [[Asparagales]]
| familia = [[Orchidaceae]]
| subfamilia = [[Apostasioideae]]
| genus = '''''Apostasia'''''
| genus_authority = [[Carl Ludwig von Blume|Blume]], [[1825]]
| subdivision_ranks = [[Species]]
| subdivision =
See text.
}}

'''''Apostasia''''' is a [[genus]] of primitive [[orchid]]s ([[family (biology)|family]] Orchidaceae), comprising 7 terrestrial [[species]].

The genus is distributed in humid areas of the [[Himalaya]]n 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 [[tubercle]]s are swollen and stalked. They lack a [[velamen]].

They bear up to 30 white or yellow [[flower]]s. 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 [[stamen]]s 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 (= pleisiomorphic).

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

The genera '''''Adactylus''''' [[Robert Allen Rolfe|Rolfe]] and '''''Mesodactylis''''' [[Nathaniel Wallich|Wall.]], '''''Neumayera''''' [[Heinrich Gustav Reichenbach|Rchb.f]] and '''''Niemeyera''''' [[Ferdinand Jacob Heinrich von Mueller |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 ==
* {{cite journal|author=Stern, W. L., V. Cheadle, and J. Thorsch|title= Apostasiads, systematic anatomy, and the origins of Orchidaceae|journal= Botanical Journal of the Linnean Society | volume=111|pages= 411–45|year = 1993}}
* {{cite journal|author=A. Kocyan, Y.-L. Qiu, P. K. Endress, and E. Conti|title= A phylogenetic analysis of Apostasioideae (Orchidaceae) based on ITS, trnL-F and matK sequences |journal= Plant Syst. Evol.|volume=247|pages=203-213|year=2004 }}

[[Category:Orchid genera]]

Apostasia - Revision history

Envoy at 07:03, 26 June 2007