ORCHIDACEAE
Pachystoma Blume, Bijdr. 376. (1825).
By: Lokesh R. Shakya
Taxon Description
Sympodial terrestrial herbs. Rhizome subterranean, swollen, fleshy. Leaves linear, plicate, sheathing at the base, narrow, glabrous, thin-textured, often withered at the time of flowering. Inflorescence arising from the rhizome, erect, usually far separated from the leaf-bearing shoot, peduncle with many brown sheaths, racemose, few- to many-flowered. Fertile bract persistent, erect, lanceolate. Flowers resupinate, hairy. Sepals subequal, not widely spreading, pubescent. Petals free, narrower than sepals. Lip sessile, 3-lobed, slightly saccate at the base, with 5-longitudinal keels. Column slender, pollinia 8, pyriform, connected by viscus at the base, sectile.
Taxon Statistics
Worldwide about 20 species, distributed in tropical and subtropical Asia to SW Pacific. One species in Nepal.
1. Pachystoma pubescens Blume, Bijdr.: 376, t. 29 (1825).
Plant ca. 40 cm. Rhizome sub-cylindrical, ca. 6 cm, leafless while flowering. Leaves 1 or 2, as long as or longer than the scape, linear, 10–40 X 0.7–1 cm, veined. Inflorescence elongate, peduncle 30–50 cm, whitish, clothed with the numerous membranous, clasping sheaths, raceme ca. 10 cm, many-flowered, rachis sparsely pubescent. Fertile bracts erect, narrowly lanceolate, 1–2 cm, acuminate, pubescent. Flowers yellowish green ca. 1.2 cm across, bracteate, yellowish green, flushid with pink; pedicel and ovary ca. 1 cm, puberulous. Sepals dissimilar, abaxially densely pubescent, 5-veined. Dorsal sepal oblong, elliptic, ca. 8.5 X 2.5 mm, acute. Lateral sepals oblong, lanceolate, ca. 7.5 X 2.2 mm, acuminate or acute. Petals narrow, spathulate, ca. 9 X 1.5 mm, recurved, blunt with narrow tip. Lip green, oblong, 7 X 6.5 mm, 3-lobed; midlobe short, sub-orbicular, recurved, lateral lobes white flushed with pink, falcate, acute, erect, disc 5-lamellate, lamellae crested. Column ca. 3.5 mm.
Distribution: Nepal, E Himalaya, Assam-Burma.
Altitudinal range: 300–400 m.
Ecology: Growing in grassland.
Flowering: February — March.