Thrixspermum, commonly known as hairseeds or 白点兰属 (bai dian lan shu), is a genus of flowering plants in the family Orchidaceae. Orchids in this genus are epiphytes, lithophytes or terrestrial plants with flat, leathery leaves and short-lived flowers with the sepals and petals more or less similar to each other. The labellum is rigidly fixed to the column and has three lobes. The side lobes are erect and the middle lobe is thick and fleshy. There are about 190 species distributed from tropical and subtropical Asia to the Western Pacific. Most species grow in lowland or tropical rainforests up to an altitude of 1,200 m.
Description Orchids in the genus Thrixspermum are epiphytic or lithophytic, rarely terrestrial, monopodial herbs with long thick roots, and flat, fleshy leaves arranged in two ranks with their bases sheathing the stem. The flowers are arranged on a pendulous or arching flowering stem arising from a leaf axil. The flowers are usually short-lived and often open for less than a day. The sepals are free from and more or less similar to each other. The petals are free from each other and similar to, but slightly shorter than the sepals. The labellum is stiffly attached to the column with a pouched base and three lobes, the side lobes erect, usually short and blunt and the middle lobe thick and fleshy. The fruit is a long, thin capsule.
Taxonomy and naming The genus Thrixspermum was first formally described in 1790 by João de Loureiro in Flora Cochinchinensis. The name Thrixspermum is derived from the Ancient Greek words (), meaning "hair" and () meaning "seed".Backer, C.A. (1936). Verklarend woordenboek der wetenschappelijke namen van de in Nederland en Nederlandsch-Indië in het wild groeiende en in tuinen en parken gekweekte varens en hoogere planten (Edition Nicoline van der Sijs).
Species The following is a list of species of Thrixspermum recognised by the Plants of the World Online as at January 2025:
Thrixspermum aberrans Schltr. Thrixspermum acuminatissimum (Rchb. f.) Rchb.f. Thrixspermum acuminatissimum subsp. acuminatissimum Thrixspermum acuminatissimum subsp. affine (Schltr.) P.O'Byrne & Gokusing Thrixspermum acutilobum J.J.Sm. Thrixspermum agamense J.J.Sm. Thrixspermum agusanense Ames Thrixspermum alabense J.J.Wood Thrixspermum alboluteum Toolmal, Schuit. & Culham Thrixspermum amesianum L.O.Williams Thrixspermum amplexicaule (Blume) Rchb.f. Thrixspermum anceps (Blume) Rchb.f. Thrixspermum ancoriferum (Guillaumin) Garay Thrixspermum angustatum L.O.Williams Thrixspermum angustifolium (Blume) Rchb.f. Thrixspermum anjunganense P.O'Byrne Thrixspermum annamense (Guillaum.) Garay Thrixspermum arachnitiforme Schltr. Thrixspermum aurantiacum J.J.Sm. Thrixspermum bellamabantae Cabactulan, Cootes & R.B.Pimentel Thrixspermum benedictii P.O'Byrne Thrixspermum bicolor P.O'Byrne, P.T.Ong & J.J.Verm. Thrixspermum borneense (Rolfe) Ridl. Thrixspermum bosuangii P.O'Byrne & Gokusing Thrixspermum brevibracteatum J.J.Sm. Thrixspermum brevicapsularis Holttum Thrixspermum brevicaule Carr Thrixspermum brevipes Schltr. Thrixspermum breviscapum (Carr) Kocyan & Schuit. Thrixspermum bromeliforme W.Suarez Thrixspermum brunnescens (Ridl.) J.J.Sm. Thrixspermum calceolus (Lindl.) Rchb.f. Thrixspermum canaliculatum J.J.Sm. Thrixspermum carinatifolium (Ridl.) Schltr. Thrixspermum carnosum (K.Schum.) Schltr. Thrixspermum caudatum P.O'Byrne & Gokusing Thrixspermum celebicum Schltr. Thrixspermum centipeda Lour Thrixspermum cerinum (Ridl.) J.J.Sm. Thrixspermum changlangensis K.Gogoi Thrixspermum chanianum P.O'Byrne & Gokusing Thrixspermum clavatum (J.Koenig) Garay Thrixspermum clavilobum J.J.Sm. Thrixspermum complanatum (J.Koenig) Schltr. Thrixspermum congestum (Bailey) Dockrill Thrixspermum conigerum J.J.Sm. Thrixspermum cootesii W.Suarez Thrixspermum cordulatum J.J.Sm. Thrixspermum corneri Holttum Thrixspermum crassifolium Ridl. Thrixspermum crassilabre (King & Pantl.) Ormerod Thrixspermum crescentiforme Ames & C.Schweinf. Thrixspermum cryptophallon P.O'Byrne & J.J.Verm. Thrixspermum cymboglossum Schltr. Thrixspermum denticulatum Schltr. Thrixspermum doctersii J.J.Sm. Thrixspermum duplocallosum Holttum Thrixspermum elmeri L.O.Williams Thrixspermum elongatum Ames Thrixspermum erythrolomum P.O'Byrne & J.J.Verm. Thrixspermum eximium L.O.Williams Thrixspermum fantasticum L.O.Williams Thrixspermum fernandeziae Cootes, Cabactulan & M.Leon Thrixspermum filifolium Schltr. Thrixspermum filiforme (Hook.f.) Kuntze Thrixspermum fimbriatum (Ridl.) J.J.Wood Thrixspermum flaccidum J.J.Sm. Thrixspermum flammeum Toolmal, Schuit. & Culham Thrixspermum fleuryi (Gagnep.) Tang & F.T.Wang Thrixspermum formosanum (Hayata) Schltr. Thrixspermum fragrans Ridl. Thrixspermum fulgens (Ridl.) Schltr. Thrixspermum fuscum (Ridl.) Merr. Thrixspermum gombakense J.J.Sm. Thrixspermum gracilicaule Schltr. Thrixspermum graeffei Rchb.f. Thrixspermum grandiflorum P.O'Byrne & J.J.Verm. Thrixspermum hiepii Aver. & Averyanova Thrixspermum hystrix (Blume) Rchb.f. Thrixspermum incurvicalcar J.J.Sm. Thrixspermum indicum Vik.Kumar, D.Verma & A.N.Rao Thrixspermum indragiriense Schltr. Thrixspermum inquinatum J.J.Sm. Thrixspermum integrum L.O.Williams Thrixspermum iodochilus Ridl. Thrixspermum japonicum (Miq.) Rchb.f. Thrixspermum javanicum J.J.Sm. Thrixspermum kipandicum P.O'Byrne & Gokusing Thrixspermum kjellbergii J.J.Sm. Thrixspermum kocyanii J.J.Wood & A.L.Lamb Thrixspermum lampongense J.J.Sm. Thrixspermum lanatum P.O'Byrne & Gokusing Thrixspermum latifolium J.J.Sm. Thrixspermum latisaccatum J.J.Sm. Thrixspermum lengguanianum P.T.Ong & P.O'Byrne Thrixspermum leucorachne Ridl. Thrixspermum ligulatum L.O.Williams Thrixspermum linearifolium Ames Thrixspermum lingiae P.O'Byrne & Gokusing Thrixspermum linusii J.J.Wood & A.L.Lamb Thrixspermum lombokense J.J.Sm. Thrixspermum longicauda Ridl. Thrixspermum longilobum J.J.Sm. Thrixspermum longipedicellatum (Joongku Lee, T.B.Tran & R.K.Choudhary) Kocyan & Schuit. Thrixspermum longipilosum J.J.Sm. Thrixspermum loogemanianum Schltr. Thrixspermum lucidum Schltr. Thrixspermum luciferum P.O'Byrne & J.J.Verm. Thrixspermum maculatum Schltr. Thrixspermum majus (Carr) Kocyan & Schuit. Thrixspermum malayanum J.J.Sm. Thrixspermum megacarpum P.O'Byrne, A.L.Lamb & P.T.Ong Thrixspermum merapohense P.O'Byrne & P.T.Ong Thrixspermum mergitiferum P.O'Byrne & J.J.Verm. Thrixspermum merguense (Hook.f .) Kuntze Thrixspermum milneri P.O'Byrne & Gokusing) Thrixspermum montanum Ridl. Thrixspermum multicolor (Ridl.) Merr. Thrixspermum neohibernicum Schltr. Thrixspermum nicolasiorum Calaramo, Cootes & Naive Thrixspermum obtusum (Blume) Rchb.f.) Thrixspermum obyrneanum Toolmal, P.T.Ong & Schuit. Thrixspermum ochraceum P.O'Byrne, P.T.Ong & J.J.Verm. Thrixspermum odoratum X.Q.Song, Q.W.Meng & Y.B.Luo Thrixspermum olidum P.O'Byrne Thrixspermum oreadum Schltr. Thrixspermum pachychilum P.O'Byrne & Gokusing Thrixspermum pardale (Ridl.) Schltr. Thrixspermum patens J.J.Sm. Thrixspermum patkeiense K.Gogoi Thrixspermum pauciflorum (Hook.f.) Kuntze Thrixspermum pellicerae Cootes, Cabactulan, R.B.Pimentel & M.Leon Thrixspermum pensile Schltr. Thrixspermum pinocchio P.O'Byrne & J.J.Verm. Thrixspermum platycaule Holttum Thrixspermum platystachys (F.M. Bailey) Schltr. Thrixspermum poilanei (Gagnep.) Tang & F.T.Wang Thrixspermum polystictum Toolmal, Schuit., & Suddee Thrixspermum ponapense Tuyama Thrixspermum praetermissum Toolmal, Schuit., & Suddee Thrixspermum psiloglottis (Ridl.) Schltr. Thrixspermum pugionifolium (Hook.f.) Schltr. Thrixspermum pulchellum (Thwaites) Schltr. Thrixspermum pulchrum Carr Thrixspermum pulverulentum (Carr) Kocyan & Schuit. Thrixspermum punctatum (Ridl.) J.J.Sm. Thrixspermum purpurascens Rchb. f. Thrixspermum pusillum (Guillaumin) Garay Thrixspermum pygmaeum (King & Pantl.) Holttum Thrixspermum quinquelobum Ames Thrixspermum raciborskii J.J.Sm Thrixspermum raciborskii subsp. brevipollinium P.O'Byrne & Ent Thrixspermum raciborskii subsp. raciborskii Thrixspermum recurvum (Hook.f.) Kuntze Thrixspermum remotiflorum J.J.Sm. Thrixspermum rimauense J.J.Wood & A.L.Lamb Thrixspermum rimiae P.O'Byrne & Ent Thrixspermum robinsonii Ames Thrixspermum roseum J.J.Sm. Thrixspermum rostratum Ames Thrixspermum rubrocalcaratum P.O'Byrne & Gokusing Thrixspermum saccatum P.O'Byrne & J.J.Verm. Thrixspermum sagoense J.J.Sm. Thrixspermum samarindae Schltr. Thrixspermum sarawakense Ames Thrixspermum sarcophyllum Garay Thrixspermum saruwatarii (Hayata) Schltr. Thrixspermum scandens P.O'Byrne Thrixspermum scopa (Rchb.f. ex Hook.f.) Holttum Thrixspermum scortechinii (Hook.f.) Kuntze Thrixspermum semiteretifolium J.J.Wood & A.L.Lamb Thrixspermum simile Tollmal, Schuit. & Utteridge Thrixspermum simum J.J.Sm. Thrixspermum squarrosum J.J.Sm. Thrixspermum stelidioides Aver. & Averyanova Thrixspermum subteres J.J.Sm. Thrixspermum subulatum (Blume) Rchb.f. Thrixspermum sumatranum J.J.Sm. Thrixspermum sutepense (Rolfe ex Downie) Tang & F.T.Wang Thrixspermum taeniophyllum Jun Y.Zhang, H.He & Yue H.Cheng Thrixspermum tahanense Carr Thrixspermum taianum P.O'Byrne & P.T.Ong Thrixspermum tenuicalcar Carr Thrixspermum teretifolium P.O'Byrne & J.J.Verm. Thrixspermum torajaense P.O'Byrne Thrixspermum tortum J.J.Sm. Thrixspermum triangulare Ames & C.Schweinf. Thrixspermum trichoglottis (Hook.f.)Kuntze Thrixspermum tsii W.H.Chen & Y.M.Shui Thrixspermum tubulatum P.O'Byrne Thrixspermum tylophorum Schltr. Thrixspermum validum J.J.Sm. Thrixspermum vanoverberghii Ames Thrixspermum ventricosum J.J.Wood & A.L.Lamb Thrixspermum walkeri Seidenf. & P.Ormerod Thrixspermum warianum Schltr. Thrixspermum weberi Ames Thrixspermum wenzelii Ames Thrixspermum westenenkii (J.J.Sm.) Kocyan & Schuit. Thrixspermum williamsianum (Kores) Ormerod Thrixspermum xantholeucum Schltr. Thrixspermum xantholomum P.O'Byrne & J.J.Verm.
Distribution Orchids in the genus Thrixspermum are found in China, Japan (including the Ryukyu Islands), Korea, Taiwan, India (including the Andaman and Nicobar Islands), Bangladesh, Nepal, Sri Lanka, Cambodia, Laos, Myanmar, Thailand, Vietnam, Borneo, Indonesia, Malaysia, the Philippines, New Guinea, the Solomon Islands, northern Australia (including Christmas Island), Fiji, New Caledonia, Samoa, Vanuatu and the Caroline Islands. About fourteen species, two of which are endemic occur in China, nine are found in Taiwan and three in Australia.
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