Thrixspermum

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 thrix (θρίξ), meaning "hair" and sperma (σπέρμα) meaning "seed".

Species
The following is a list of species of Thrixspermum recognised by the World Checklist of Selected Plant Families as at January 2019:


 * Thrixspermum aberrans Schltr. 1913
 * Thrixspermum acuminatissimum (Rchb. f.) Rchb.f. 1868
 * Thrixspermum acuminatissimum subsp. acuminatissimum
 * Thrixspermum acuminatissimum subsp. affine (Schltr.) P.O'Byrne & Gokusing (2016)
 * Thrixspermum acutilobum J.J.Sm. 1921
 * Thrixspermum agamense J.J.Sm. 1927
 * Thrixspermum agusanense Ames 1915
 * Thrixspermum alabense J.J.Wood (2010)
 * Thrixspermum amesianum L.O.Williams 1938
 * Thrixspermum amplexicaule (Bl.) Rchb. f. 1867
 * Thrixspermum anceps (Blume) Rchb.f. (1868)
 * Thrixspermum ancoriferum (Guillaumin) Garay (1972)
 * Thrixspermum angustatum L.O.Williams 1938)
 * Thrixspermum angustifolium (Blume) Rchb.f. (1868)
 * Thrixspermum anjunganense P.O'Byrne (2016)
 * Thrixspermum annamense ( Guillaum. ) Garay 1972
 * Thrixspermum arachnitiforme Schltr. 1921
 * Thrixspermum aurantiacum J.J.Sm. 1920
 * Thrixspermum bicolor P.O'Byrne, P.T.Ong & J.J.Verm. (2015)
 * Thrixspermum borneense (Rolfe) Ridl. (1896)
 * Thrixspermum bosuangii P.O'Byrne & Gokusing (2016)
 * Thrixspermum brevibracteatum J.J.Sm. 1928
 * Thrixspermum brevicapsularis Holttum 1947
 * Thrixspermum brevicaule Carr 1929
 * Thrixspermum brevipes Schltr. 1913
 * Thrixspermum breviscapum (Carr) Kocyan & Schuit. (2014)
 * Thrixspermum bromeliforme W.Suarez (2009)
 * Thrixspermum brunnescens (Ridl.) J.J.Sm. (1933)
 * Thrixspermum calceolus (Lindl.) Rchb.f. (1868)
 * Thrixspermum canaliculatum J.J.Sm. (1914)
 * Thrixspermum carinatifolium (Ridl.) Schltr. (1911)
 * Thrixspermum carnosum (K.Schum.) Schltr. (1911)
 * Thrixspermum caudatum P.O'Byrne & Gokusing (2016)
 * Thrixspermum celebicum Schltr. 1911
 * Thrixspermum centipeda Lour 1790
 * Thrixspermum cerinum (Ridl.) J.J.Sm. (1933)
 * Thrixspermum chanianum P.O'Byrne & Gokusing (2016)
 * Thrixspermum clavatum (J.Koenig) Garay (1972)
 * Thrixspermum clavilobum J.J.Sm. 1928
 * Thrixspermum collinum Schltr. 1913
 * Thrixspermum complanatum (J.Koenig) Schltr. (1911)
 * Thrixspermum congestum (Bailey) Dockrill  1967
 * Thrixspermum conigerum J.J.Sm. (1921)
 * Thrixspermum cootesii W.Suarez (2009)
 * Thrixspermum cordulatum J.J.Sm. 1927
 * Thrixspermum corneri Holttum 1947
 * Thrixspermum crassifolium Ridl.
 * Thrixspermum crassilabre (King & Pantl.) Ormerod 2004
 * Thrixspermum crescentiforme Ames & C.Schweinf.  1920
 * Thrixspermum cryptophallon P.O'Byrne & J.J.Verm. (2015)
 * Thrixspermum cymboglossum Schltr. 1911
 * Thrixspermum denticulatum Schltr. 1906
 * Thrixspermum doctersii J.J.Sm. 1914
 * Thrixspermum duplocallosum Holttum 1947
 * Thrixspermum elmeri L.O.Williams 1938
 * Thrixspermum elongatum Ames 1915
 * Thrixspermum erythrolomum P.O'Byrne & J.J.Verm. (2008)
 * Thrixspermum eximium L.O.Williams 1938
 * Thrixspermum fantasticum L.O.Williams 1938
 * Thrixspermum fernandeziae Cootes, Cabactulan & M.Leon (2017)
 * Thrixspermum filifolium Schltr. 1911
 * Thrixspermum filiforme (Hook.f.) Kuntze (1891)
 * Thrixspermum fimbriatum (Ridl.) J.J.Wood 1994
 * Thrixspermum flaccidum J.J.Sm. 1920
 * Thrixspermum fleuryi (Gagnep.) Tang & F.T.Wang (1951)
 * Thrixspermum formosanum (Hayata) Schltr. (1919)
 * Thrixspermum fragrans Ridl. 1921
 * Thrixspermum fulgens (Ridl.) Schltr. (1911)
 * Thrixspermum fuscum (Ridl.) Merr. (1921)
 * Thrixspermum gombakense J.J.Sm. 1928
 * Thrixspermum gracilicaule Schltr. 1907
 * Thrixspermum graeffei Rchb.f.
 * Thrixspermum grandiflorum P.O'Byrne & J.J.Verm. (2008)
 * Thrixspermum hiepii Aver. & Averyanova(2006)
 * Thrixspermum hystrix (Blume) Rchb.f.(1874)
 * Thrixspermum incurvicalcar J.J.Sm. 1926
 * Thrixspermum indicum Vik.Kumar, D.Verma & A.N.Rao (2017)
 * Thrixspermum indragiriense Schltr. 1907
 * Thrixspermum inquinatum J.J.Sm. 1907
 * Thrixspermum integrum L.O.Williams 1938
 * Thrixspermum iodochilus Ridl. 1922
 * Thrixspermum japonicum (Miq.) Rchb. f. 1878
 * Thrixspermum javanicum J.J.Sm. 1921
 * Thrixspermum kipandicum P.O'Byrne & Gokusing (2016)
 * Thrixspermum kjellbergii J.J.Sm. 1933
 * Thrixspermum kocyanii J.J.Wood & A.L.Lamb (2011)
 * Thrixspermum lampongense J.J.Sm. 1917
 * Thrixspermum lanatum P.O'Byrne & Gokusing (2016)
 * Thrixspermum latifolium J.J.Sm. 1917
 * Thrixspermum latisaccatum J.J.Sm. 1920
 * Thrixspermum lengguanianum P.T.Ong & P.O'Byrne (2011)
 * Thrixspermum leucorachne Ridl.
 * Thrixspermum ligulatum L.O.Williams 1938
 * Thrixspermum linearifolium Ames 1915
 * Thrixspermum lingiae P.O'Byrne & Gokusing (2016)
 * Thrixspermum linusii J.J.Wood & A.L.Lamb (2011)
 * Thrixspermum lombokense J.J.Sm. 1925
 * Thrixspermum longicauda Ridl.
 * Thrixspermum longilobum J.J.Sm. 1920
 * Thrixspermum longipedicellatum (Joongku Lee, T.B.Tran & R.K.Choudhary) Kocyan & Schuit. (2014)
 * Thrixspermum longipilosum J.J.Sm. 1922
 * Thrixspermum loogemanianum Schltr. 1911
 * Thrixspermum lucidum Schltr. 1911
 * Thrixspermum luciferum P.O'Byrne & J.J.Verm. (2004)
 * Thrixspermum maculatum Schltr. 1906
 * Thrixspermum majus (Carr) Kocyan & Schuit. (2014)
 * Thrixspermum malayanum J.J.Sm. 1921
 * Thrixspermum megacarpum P.O'Byrne, A.L.Lamb & P.T.Ong (2015)
 * Thrixspermum merapohense P.O'Byrne & P.T.Ong (2015)
 * Thrixspermum mergitiferum P.O'Byrne & J.J.Verm. (2004)
 * Thrixspermum merguense (Hook.f .) Kuntze 1996
 * Thrixspermum milneri P.O'Byrne & Gokusing (2016)
 * Thrixspermum montanum Ridl. 1913
 * Thrixspermum multicolor (Ridl.) Merr. (1921)
 * Thrixspermum musciflorum A.S.Rao & Joseph 1971
 * Thrixspermum obtusum (Blume) Rchb.f. (1868)
 * Thrixspermum ochraceum P.O'Byrne, P.T.Ong & J.J.Verm. (2015)
 * Thrixspermum odoratum X.Q.Song, Q.W.Meng & Y.B.Luo (2009)
 * Thrixspermum olidum P.O'Byrne (2016)
 * Thrixspermum pachychilum P.O'Byrne & Gokusing (2016)
 * Thrixspermum pardale (Ridl.) Schltr. (1911)
 * Thrixspermum patens J.J.Sm. 1921
 * Thrixspermum pauciflorum (Hook.f.) Kuntze (1891)
 * Thrixspermum pensile Schltr. 1911
 * Thrixspermum pinocchio P.O'Byrne & J.J.Verm. (2008)
 * Thrixspermum platycaule Holttum (1947)
 * Thrixspermum platystachys (F.M. Bailey) Schltr. 1911
 * Thrixspermum poilanei (Gagnep.) Tang & F.T.Wang (1951)
 * Thrixspermum ponapense Tuyama 1940
 * Thrixspermum psiloglottis (Ridl.) Schltr. (1911)
 * Thrixspermum pugionifolium (Hook.f.) Schltr. (1911)
 * Thrixspermum pulchellum (Thwaites) Schltr. (1911)
 * Thrixspermum pulchrum Carr 1932
 * Thrixspermum pulverulentum (Carr) Kocyan & Schuit. (2014)
 * Thrixspermum punctatum (Ridl.) J.J.Sm. (1933)
 * Thrixspermum purpurascens Rchb. f.
 * Thrixspermum pusillum (Guillaumin) Garay (1972)
 * Thrixspermum pygmaeum (King & Pantl.) Holttum (1960)
 * Thrixspermum quinquelobum Ames 1915
 * Thrixspermum raciborskii J.J.Sm
 * Thrixspermum raciborskii subsp. brevipollinium P.O'Byrne & Ent (2016)
 * Thrixspermum raciborskii subsp. raciborskii
 * Thrixspermum recurvum (Hook.f.) Kuntze (1891)
 * Thrixspermum remotiflorum J.J.Sm. 1906
 * Thrixspermum rimauense J.J.Wood & A.L.Lamb (2011)
 * Thrixspermum rimiae P.O'Byrne & Ent (2016)
 * Thrixspermum robinsonii Ames 1915
 * Thrixspermum roseum J.J.Sm. 1918
 * Thrixspermum rostratum Ames 1915
 * Thrixspermum rubrocalcaratum P.O'Byrne & Gokusing (2016)
 * Thrixspermum saccatum P.O'Byrne & J.J.Verm. (2008)
 * Thrixspermum sagoense J.J.Sm. 1928
 * Thrixspermum samarindae Schltr. 1906
 * Thrixspermum sarawakense Ames (1921)
 * Thrixspermum sarcophyllum Garay (1974)
 * Thrixspermum saruwatarii (Hayata) Schltr. 1919
 * Thrixspermum scandens P.O'Byrne (2016)
 * Thrixspermum scopa (Rchb.f. ex Hook.f.) Holttum (1947)
 * Thrixspermum scortechinii (Hook.f.) Kuntze (1891)
 * Thrixspermum semiteretifolium J.J.Wood & A.L.Lamb (2010)
 * Thrixspermum simum J.J.Sm. 1927
 * Thrixspermum squarrosum J.J.Sm. 1921
 * Thrixspermum stelidioides Aver. & Averyanova (2006)
 * Thrixspermum subteres J.J.Sm.
 * Thrixspermum subulatum (Blume) Rchb.f. (1868)
 * Thrixspermum sumatranum J.J.Sm. 1920
 * Thrixspermum sutepense (Rolfe ex Downie) Tang & F.T.Wang (1951)
 * Thrixspermum tahanense Carr 1930
 * Thrixspermum taianum P.O'Byrne & P.T.Ong (2015)
 * Thrixspermum tenuicalcar Carr 1932
 * Thrixspermum teretifolium P.O'Byrne & J.J.Verm. (2008)
 * Thrixspermum torajaense P.O'Byrne 1998
 * Thrixspermum tortum J.J.Sm. 1914
 * Thrixspermum triangulare Ames & C.Schweinf. 1920
 * Thrixspermum trichoglottis (Hook.f.)Kuntze 1896
 * Thrixspermum tsii W.H.Chen  &  Y.M.Shui 2005
 * Thrixspermum tubulatum P.O'Byrne (2016)
 * Thrixspermum tylophorum Schltr. 1911
 * Thrixspermum validum J.J.Sm. 1908
 * Thrixspermum vanoverberghii Ames 1914
 * Thrixspermum ventricosum J.J.Wood & A.L.Lamb (2011)
 * Thrixspermum walkeri Seidenf. &  P.Ormerod  1995
 * Thrixspermum warianum Schltr. 1913
 * Thrixspermum weberi Ames 1922
 * Thrixspermum wenzelii Ames 1915
 * Thrixspermum westenenkii (J.J.Sm.) Kocyan & Schuit. (2014)
 * Thrixspermum williamsianum (Kores) Ormerod (1996)
 * Thrixspermum xantholeucum Schltr.
 * Thrixspermum xantholomum P.O'Byrne & J.J.Verm. (2008)
 * Thrixspermum zollingeri (Rchb.f.) Rchb.f. (1868)

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.