The genus Thrixspermum Lour. comprises appro-ximately 168 species distributed from Sri Lanka and the Himalayan region and Taiwan, southeast through Malesia to north Australia and the Pacific islands, and east to Fiji and Samoa. About 16 species have been found in China, mostly found in the southern provinces and on the island of Taiwan. This genus is characterized by its saccate but not truly spurred lip with a partly hairy or papillose front wall callus, short column with a long foot; 4 unequal pollinia united in pairs on a short broad stipe.
During a botanical survey in Hainan, China in 2014, an orchid species was discovered and identified as T. longipedicellatum (Joongku Lee, T. B. Tran & R. K. Choudhary) Kocyan & Schuit., a new record to Chinese flora.
Thrixspermum longipedicellatum was first reported as a species of Cordiglottis J. J. Sm., which differs from Thrixspermum mostly in its terete or laterally flattened leaves and minor lip characters; Molecular systematic studies found Cordiglottis deeply nested in Thrixspermum, and then considered to be a synonym of Thrixspermum[1, 3-4].
Thrixspermum longipedicellatum (Joongku Lee, T. B. Tran & R. K. Choudhary) Kocyan & Schuit., Phytotaxa 161: 75. 2014. -Cordiglottis longipedi-cellata Joongku Lee, T. B. Tran & R. K. Choudhary, Ann. Bot. Fenn. 50: 95. 2013. Type: Vietnam: Khanh Hoa Province, HonBa Nature Reserve, J. Lee et al. 10 April 2012, HIKK, 1316 (holotype, HN). (长柄白点兰 新拟 Fig. 1)
Epiphytic herb, up to 20 cm long. Stem up to 8 cm long. Leaves 4-7, 10-15 cm×0.8-1.2 cm, pendulous, iridiform and unifacial, distichous, imbri-cate at base, fleshy. Inflorescence lateral, 1-flowered, scape 1.0-1.5 cm long; peduncle 1.0-1.5 cm long, glabrous. Floral bracts triangular, thin, apex acute, 2-3 mm×1-1.5 mm. Flowers white, lip with reddish-purple stripes or spots at base and margin of side lobes, disc and centre midlobe bright yellow and powdery. Pedicel and ovary 1.2-1.4 cm. Dorsal sepal 5.5-6 mm×3.8-4 mm, elliptic, apex acute. Lateral sepals 7-7.5 mm×4-4.5 mm, trapeziform, apex acute. Petals 5.5-6 mm×4-4.5 mm, ovate, apex abtuse. Lip 6-6.5 mm×5 mm, saccate, more or less sigmoid, without a spur, 3-lobed, callus fleshy, apex obtuse, sac, callus and disco covered yellow powder; side lobes erect, slightly angular-round, 3-4 mm long; midlobe almost flat at apex, slightly decurved, 6-7 mm×3-4 mm. Column 3.5-4 mm long; foot prominent, nearly as long; anther cap ovate.
Flowering period: April to July.
Specimens examined: China: Hainan Province, Wuzhishan City, Qingchunling Mountain, 9 May, 2016, M. Z. Huang 160509001 (ATCH).
Distribution: Hainan, China. Vietnam.
Habitat: T. longipedicellatum is epiphyticon the crown of mixed evergreen and sub-temperate forests about 900-1 300 m a.s.l.
Note: Compared with the species from Vietnam (based on the original description), the flower of specimens from China shows wider sepals and petals, longer column and foot, powdery surface of callus on midlobe of the lip, which would most likely displays the geographic variation. The last character is the same as its closely related species, T. pulverulentum, which is known only from Tembeling, Pahang, Malaysia. However, the former differs in having a non-prickly scape, a longer pedicel, and a longer column-foot.
Conservation status: Three populations of T. longipedicellatum were discovered by a distance of around 50 km from each other in Hainan, China. However, crown habitats make it difficult to survey, and currently sufficient quantitative data of the population of this taxon are not available, preventing assessment under any specific criteria. Therefore, we recommend this taxon to be kept under Data Deficient (DD) category of IUCN Red List.Acknowledgment: We thank Mr. Deng Qifei for the association of botanical survey, Dr. Jiang Kai (Shanghai Chenshan Botanical Garden) and Dr. Li Lei (CATAS) for their help with the literature; Assistant Researcher Zheng Li-cheng for reading and revising the manuscript.
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