Genus Didymoplexis

Didymoplexis Griff.,
Calc. J. Nat. Hist. 4 (1844) 383, t. 17

Leafless terrestrial plants lacking chlorophyll. Inflorescence a few- to many-flowered raceme arising from a tuber-like underground rhizome. Flowers opening in succession, small, resupinate, usually brownish or whitish. Sepals and petals all mutually connate for at least half their length, except that the lateral sepals are only at the base connate with the petals. Petals not much smaller than the dorsal sepal. Lip without spur, not mobile. Stigma situated near the apex of the column. Column-foot present. Pollinia 4, mealy, caudicles absent, stipe absent, viscidium present.

Southern and East Africa, Madagascar, Southeast Asia, Malaysia, Indonesia, the Philippines, Papua New Guinea, Australia, Pacific islands, east to Samoa. About 10 species; in New Guinea 4 species.

Terrestrial in lowland rainforest, often associated with bamboo.

Related to Didymoplexiella (not occurring in New Guinea), but the column has a more distinct foot and lacks the apical stelidia of Didymoplexiella. Didymoplexis is often confused with Gastrodia but easily distinguished from that genus in that the lateral sepals are almost free from the petals, while in Gastrodia they are long adnate to the petals. The position of the stigma is also different. As one of the holomycotrophic orchid genera (formerly and still often wrongly called 'saprophytes ), Didymoplexis is not in cultivation, but occurs sometimes spontaneously in botanical gardens in the region.