Volume 12 > Part 3 > Year 2022 > Page 707 > Orchidaceae > Ceratostylis

6. Ceratostylis thailandica Seidenf.wfo-0000834109

Bot. Tidsskr. 65: 134. 1969; Seidenf., Opera Bot. 89: 116, fig. 67, t. IXd. 1986; Sittisudjathum, Wild Orchids Thail. 1 [in Thai]: 235, colour photos on pp. 140–141. 2009. Fig. 377; Plate LVIII: 3.

Accepted Name : This is currently accepted.

Description : Epiphyte, 11.8‒12.5(‒16.5) cm tall. Stem 4‒8 by 0.3‒0.4 cm; sheaths covering the whole stem, 2‒5.2 by 1.2‒1.4 cm. Leaves solitary, dorsoventrally flattened, oblong-lanceolate, 5.5‒8.5(‒13.5) by 1.2‒1.8 cm, base gradually narrowed to a short stalk, apex generally bilobed. Inflorescence single-flowered, 1‒1.4 cm long; inflorescence bracts 2, dark brown, 0.8‒1 by 0.5‒0.6 cm, 5-veined; floral bract smaller than inflorescence bracts. Flower white with two reddish purple keels on the lip, 0.8‒1 by ca 0.9 cm. Sepals: dorsal sepal ovate, 5.5‒10 by 2‒5 mm, 3- to 5-veined; lateral sepals ovate-lanceolate, 3.5‒9 by 1‒4.5 mm, 4- to 5-veined. Petals lanceolate, acute to rounded, 5.3‒6 by 1.7‒3 mm, 3-veined, glabrous, entire. Labellum spathulate, 5‒8.5 mm long, with extended mesochile and lower part of epichile; epichile 4.5‒5 by 2‒3 mm; mesochile 1‒2 by 1.5‒2 mm; hypochile ca 1.5 by 0.5‒1 mm, ornamented by 2 longitudinal warty keels, 3-veined from mesochile, margin entire, thickened and fleshy near apex, apex obtuse. Column 1.5‒2.5 by ca 2 mm; anther cordate, 1.5‒2 by 1‒1.5 mm; pollinia 0.5‒0.7 by 0.3‒0.4 mm. Ovary (including pedicel) 7‒8 mm long, hairy. Capsule 1.8‒2 by 0.5‒0.6 cm.

Thailand : PENINSULAR: Nakhon Si Thammarat (Khao Luang – type: Seisenfaden & Smitinand GT 6329, holotype -C).

Distribution : Endemic.

Ecology : Growing as an epiphyte in evergreen forests, 1,000‒1,350(‒1,700) m alt. Flowering: mainly June‒August, but also recorded in January.

Vernacular : Sae ma khao luang (แส้ม้าเขาหลวง).