e-Flora of Thailand

Volume 12 > Part 1 > Year 2011 > Page 138 > Orchidaceae > Habenaria

38. Habenaria rostrata Wall. ex Lindl.

Gen. Sp. Orchid. Pl.: 325. 1835; Hook.f., Fl. Brit. India 6: 146, 1890; Seidenf. & Smitinand, Orchids Thail.: 36. 1959; Seidenf., Dansk Bot. Ark. 31(3): 110, fig. 67. 1977; Opera Bot. 114: 63. 1992; S.C.Chen & P.J.Cribb in Z.Y. Wu et al. (eds), Fl. China 25: 156. 2009; Kurzweil, Thai Forest Bull., Bot., special issue: 59. 2009. Fig. 79: Plate XI: 2.


Accepted Name : This is currently accepted.



Synonyms & Citations :

Platanthera rostrata Lindl. In Wall., Numer. List: 7051. 1832. nom. inval.


Description : Flowering shoots glabrous, 17–38 cm tall. Foliage leaves 2–4. cauline, scattered in the lower stem part, oblong-oblanceolate, acute, mucronate, 4.5–12 by 0.4–1.4 cm. Sterile bracts 6–11, suberect, lanceolate, acuminate, 2–5 cm long, margins denticulate or shortly hairy. Inflorescence semi-dense, (3–)7- to 18-flowered; rachis 2–7 cm long; floral bracts lanceolate, acuminate, 9–18 by 1–3 mm, margins shortly hairy. Flowers 1–1.2 cm in diameter (excluding labellum), mostly brown, pinkish-brown, orange-brown or orange, also recorded as yellow or white with dark brown labellum, spur sometimes green. Sepals obtuse or subacute, margins mostly denticulate; dorsal sepal erect, suborbicular, (3–)3.5–4.2 by 3–4 mm; lateral sepals reflexed, prominently obliquely ovate, 5.5–7 by 3–4.8 mm. Petals forming a hood with the dorsal sepal, triangular-oblong, subacute, 3–4.2 by 1.7–1.8 mm, basally united with the lateral sepals and the labellum, margins mostly denticulate. Labellum 8–14 mm long, 3-lobed above a short united part, with a collar in front of the spur mouth; midlobe linear, 7–12 by 0.8–1.2 mm; side lobes linear, (6–)9–12 by 0.5–0.8 mm; spur cylindric, 17–25 mm long, distally clavate. Column 2.5–3 mm long; anther canals 2–3 mm long, straight or slightly curved upwards; auricles prominent and high. Ovary (including pedicel) 19–27 mm long, beaked, hairy. Capsule elliptic fusiform, ca 22.3 mm long and 4.1 mm in diameter, beak elongate.


Thailand : NORTHERN: Mae Hong Son, Chiang Mai; NORTH-EASTERN: Sakon Nakhon, Mukdahan; EASTERN: Amnat Charoen, Si Sa Ket, Ubon Ratchathani; SOUTH-WESTERN: Ratchaburi; SOUTH-EASTERN: Chanthaburi.


Distribution : Myanmar (type), Laos, Vietnam, S China (Sichuan, Yunnan).


Ecology : In open areas in deciduous or seasonal evergreen forests, in pine forests and savanna; 50–1,120 m alt. Flowering: mainly July–September.


Vernacular : Ua kaem cham (อั้วแก้มช้ำ).


Main

Figure 79
Plate XI: 2
Habenaria rostrata Wall. ex Lindl.