Bijdr. (1825) 423
Sympodial terrestrial plants without distinct rhizomes, all parts glabrous. Stem elongated, few- to many-leaved, often branched, not fleshy. Leaves spirally arranged, sheathing at the base, not plicate, persistent, convolute, thin-textured; apices tubular-filiform. Inflorescence a terminal panicle. Ovary not articulated from the pedicel. Flowers small, not resupinate. Sepals free. Petals free, rather similar to the sepals. Lip without spur, not mobile, similar to the petals. Column-foot absent. Fertile anthers 2, clasping the style, pollen not aggregated into pollinia, powdery.
Sri Lanka, Nepal, India (Assam), Burma, Thailand, Cambodia, Vietnam, Malaysia, Singapore, Indonesia, Brunei, the Philippines, Papua New Guinea, Australia (Queensland). About 8 species; in New Guinea one, non-endemic, species [Apostasia wallichii R.Br.].
Terrestrial in primary evergreen forest, altitude (20-) 100 to 1700 m.
Apostasia is a genus of terrestrial forest plants with very simple inconspicuous flowers, in which the lip is similar to the petals. Apart from Paphiopedilum and its Cypripedioid relatives, Apostasia is the only orchid genus that has two fertile anthers. It is, however, much more closely related to Neuwiedia than to Paphiopedilum. Apostasia and Neuwiedia together comprise the subfamily Apostasioideae, which is now firmly established as being the most basic subfamily within the orchid family (which is not the same thing as saying that it is the most 'primitive' group of orchids, because that depends on the characters considered). Species of Apostasia possess hardly any horticultural potential, and as they are difficult to keep alive they are rarely if ever seen in cultivation.