Gastrodia R. Brown, Prodr. 330. 1810.
Synonyms:
Epiphanes Blume, Bijdr.: 421 (1825).
Gamoplexis Falc. ex Lindl., Gard. Chron. 1847: 103 (1847).
Demorchis D.L.Jones & M.A.Clem., Orchadian 14(8: Sci. Suppl.): xiii (2004).
Description:
Herbs terrestrial, leafless, holomycotrophic. Rhizomes horizontal, tuberous, cylindric, sometimes slightly coralloid, slightly fleshy, usually densely noded. Inflorescence erect, terminal, noded below middle, nodes with tubular or scalelike sheaths, glabrous, yellowish brown or dull brown, usually few to many flowered, rarely 1-flowered, sometimes elongating in fruit. Flowers spreading or nodding, campanulate, urceolate, or cylindric, resupinate or not, cream-brown, yellowish brown, or dull brown, occasionally greenish brown, lip often lighter brown and sometimes with orange markings; pedicel usually elongating in fruit. Sepals and petals united and forming a perianth tube, only apical portions free; perianth tube sometimes dilated and saccate at base, sometimes with a deep sinus between lateral sepals, outer surface often verrucose; petals much smaller than sepals; lip enclosed within perianth tube, adnate to apex of column foot, usually small, usually clawed at base, simple or 3-lobed; disk with a pair of globose calli at base. Column elongate, with a short but distinct column foot at base, winged toward apex, sometimes with a pair of toothlike projections at apex; anther borne on a filament, large, subterminal, incumbent; pollinia 2, granular-farinaceous, usually composed of friable massulae,without caudicles; stigma raised, shield-shaped. Capsule erect.
Distribution:
Cameroon, Réunion, Russian Far East to Trop. Asiaand New Zealand, Vanuatu
Species:

Gastrodia africana Kraenzl. SW. Cameroon.
Gastrodia ballii P.J.Cribb & Browning S. Malawi, NE. Zimbabwe, WC. Mozambique
Gastrodia elatoides W.C.Huang, G.W.Hu & Q.F.Wang Madagascar.
Gastrodia madagascariensis Schltr. ex H.Perrier NE. Madagascar.
Gastrodia rwandensis Eb.Fisch. & Killmann Rwanda
Gastrodia sesamoides R.Br. S. & E. Australia
Gastrodia similis Bosser  Réunion.

World Checklist of Monocotyledons. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the Internet; http://www.kew.org/wcsp/monocots/ accessed 31/03/2020
Bibliography and References:
Olszewski TS. 2004 A provisional checklist of the continental African Orchidaceae. 5. Vanilloideae. Pol. Bot. J. 49. 123-134
Hatch ED. 1999 The New Zealand genera: 9. Gastrodia. New Zealand Native Orchid Group J. no. 72. 16-17 (1999)
Bates R. 1977 Our rarest orchids: no.6 Native Orchid Soc. S. Austral. J. 1. (7): 5 (1977)
WEI-CHANG HUANG,Gastrodia elatoides (Orchidaceae: Epidendroideae: Gastrodieae), a new holomycoheterotrophic orchid from Madagascar, Phytotaxa 349 (2): 167–172-2018