Didymoplexis Griffith, Calcutta J. Nat. Hist. 4: 383. 1844.
Synonyms:
Leucorchis Blume, Mus. Bot. 1: 31 (1849).
Apetalon Wight, Icon. Pl. Ind. Orient. 5: 22 (1851).
Epiphanes Rchb.f. in B.Seemann, Fl. Vit.: 295 (1868), nom. illeg.
Description:
Herbs, terrestrial, small, holomycotrophic. Rhizome fusiform, tuberous, fleshy, neck sometimes with a few filiform roots. Stem erect, slender, with a few scalelike sheaths near base, leafless, glabrous. Inflorescence erect, terminal, racemose, with 1 to several flowers; floral bracts small. Flowers spreading, resupinate, often ephemeral, white or pale yellowish brown; pedicel elongating in fruit. Sepals and petals connate at base and forming a short tube; dorsal sepal and petals connate for ca. 1/2 their length and forming a porrect hood; lateral sepals usually connate for more than 1/2 of their length, deflexed distally; lip adnate with column foot at base, free from sepals and petals, not spurred, entire or weakly 3-lobed; disk with 1 or more basal glands and often papillate. Column elongate, dilated and with 2 wings at apex, wings forming short, toothlike stelidia, with distinct column foot at base; anther subterminal, borne on a short filament; pollinia 4, in 2 pairs, granular-farinaceous, ecaudiculate, each pair directly attached to a sticky viscidium; rostellum erect, transverse; stigma broad, placed directly below rostellum. Capsule erect, fusiform.
Type species: Didymoplexis pallens Griff.
Notes:
Didymoplexis Griff. (Griffith 1844: 383) is a genus of 21 terrestrial, holomycotrophic, achlorophyllous species found in tropical and southern African, tropical Asia from India and the Ryukyu Islands eastwards through Malesia to Australia and the Pacific archipelagos to Fiji and Samoa (Govaerts 2019). Until 2011 no true Didymoplexis had been recorded from Madagascar (Didymoplexis madagascariensis (Schltr. ex H.Perrier) Summerh. (Summerhayes 1953: 131) is now considered Gastrodia madagascariensis Schltr. ex Martos & Bytebier (Martos et al. 2015: 048). Cribb et al. recorded Didymoplexis verrucosa from northern Madagascar in 2011 (Cribb et al. 2011) and two years later (Cribb et al. 2013) described Didymoplexis avaratraensis and Didymoplexis recurvata, also from northern Madagascar and wondered how many species of Didymoplexis there were on the island.
Distribution:
Trop. & S. Africa to W. Pacific
Cultivation:
Not in cultivation.
Species in the genus Didymoplexis

References:
Olszewski TS. 2004 A provisional checklist of the continental African Orchidaceae. 5. Vanilloideae. Pol. Bot. J. 49. 123-134 Kurzweil H. 1987 Developmental studies in orchid flowers I: Epidendroid and vandoid species. Nordic J. Bot. 7. 427-42.; New species in Orchidaceae from Madagascar by Johan Hermans, Landy Rajaovelona & Phillip Cribb, Kew Bulletin 15 March 2021; POWO (2022). "Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Published on the Internet; http://www.plantsoftheworldonline.org/ Retrieved 28 November 2022."