Volume 12 > Part 1 > Year 2011 > Page 136 > Orchidaceae > Habenaria

37. Habenaria rostellifera Rchb.f.

Otia Bot. Hamburg.: 34. 1878; Seidenf. & Smitinand, Orchids Thail.: 36. 1959; Seidenf., Dansk Bot. Ark. 31(3): 108, fig. 66. 1977; Opera Bot. 114: 63. 1992; Seidenf. & J.J.Wood, Orchids Penins. Malays. Singap.: 113, fig. 48. 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: 56. 2009. Fig. 78; Plate XI: 1.

Accepted Name : This is currently accepted.

Synonyms & Citations :

Description : Flowering shoots glabrous, 16–50 cm tall. Foliage leaves 2–4, cauline, scattered in the lower stem half, oblong-oblanceolate, acute, mucronate, 4.3–7(–13) by 0.5–1.4 cm. Sterile bracts 5–8(–11), suberect, lanceolate, acuminate, 2–5.3 cm long. Inflorescence semi-dense, (3–)5 to 17-flowered; rachis 1.6–5 cm long; floral bracts lanceolate, acuminate, 10–15 by 1.8–3 mm, margins shortly hairy. Flowers 1–1.5 cm in diameter, mostly pale pink, brown or white, lateral sepals usually with brown or green blotch, also reported with dark sepals and white petals; margins of dorsal sepal and petals mostly denticulate or shortly hairy. Sepals obtuse or subacute; dorsal sepal erect, suborbicular, 3.9–5.4 by 3–5 mm; lateral sepals reflexed, strongly obliquely ovate, 5.8–8 by 3.3–5.4 mm. Petals forming a hood with the dorsal sepal, triangular-oblong, subacute, 4–5 by 1–2.1 mm, basally united with the lateral sepals and the labellum. Labellum 7–13 mm long, 3-lobed above a short united part, with a 3–4 mm long and weakly 3-lobed erect tongue in front of the spur mouth; midlobe linear, 5.5–12 by 1–1.6 mm; side lobes linear, 7–11.5 by 0.5–1 mm; spur cylindric, 15–25 mm long, geniculate, distally clavate. Column 3–4 mm long; anther canals 3–5 mm long, geniculately bent upwards; stigmas 3–4 mm long. Ovary (including pedicel) (17–)20–25 mm long, beaked. Capsule sessile, elliptic-fusiform, to 25 mm long and 4.5 mm in diameter, with an elongate beak.

Thailand : NORTHERN: Chiang Mai, Lamphun, Phrae, Sukhothai; NORTH-EASTERN: Phetchabun, Loei; EASTERN: Chaiyaphum; SOUTH-WESTERN: Kanchanaburi; CENTRAL: Lop Buri; SOUTH-EASTERN: Sa Kaeo, Prachin Buri, Rayong, Chanthaburi, Trat; PENINSULAR: Chumphon, Surat Thani, Nakhon Si Thammarat, Phatthalung [fide Seidenf., Dansk Bot. Ark. 31(3): 110. 1977], Trang, Songkhla, Pattani.

Distribution : S China, Laos, Cambodia (type), Vietnam, Peninsular Malaysia.

Ecology : In open areas in deciduous forests, scrub vegetation or in savanna over granite, also in marshy places; from near sea level to 1,120 m alt. Flowering: mainly June–September.

Vernacular : Ya man pu (หญ้ามันปู), nang ua dok si som (นางอั้วดอกสีส้ม).

Notes: Collections, doubtfully of this species, were also made in Saraburi Province in central Thailand.