口盖花蜘蛛兰 kou gai hua zhi zhu lan

Arachnis bella (H. G. Reichenbach) J. J. Smith.

Stems usually 20-30 cm, ca. 1 cm in diam., stout, rigid, with many nodes. Leaves many, sparsely distichous; leaf blade narrowly oblong, 13-16 × 2.5-3 cm, leathery, obtuse and unequally bilobed. Inflorescences often 2 or 3, ascending, racemose, 12-18 cm, sparsely 2- or 3-flowered; peduncle 5-12 cm, with 3-6 tubular sheaths; floral bracts broadly ovate, 1-1.7 cm. Flowers large, opening widely, yellow, densely marked with reddish brown transverse stripes; pedicel and ovary ca. 3 cm. Dorsal sepal ± obovate-oblong, ca. 3 × 1 cm, obtuse; lateral sepals obovate-oblong, ca. 2.7 × 0.8 cm, obtuse. Petals narrowly oblong, ca. 2.7 × 0.7 cm, obtuse; lip somewhat pandurate, ca. 14 mm, 3-lobed; claw ca. 2 mm; lateral lobes erect, subsquare, ca. 4 × 4 mm, obliquely truncate; mid-lobe nearly obovate-cuneate, ca. 8 × 9 mm, base contracted, apex emarginate, with a recurved, calluslike appendage in sinus, margin irregularly denticulate, with a thickened keel from base to apex; disk with a bilobed callus and a movable lidlike appendage covering it; sac small, ca. 3 × 2 mm. Column ca. 8 mm, stout. Fl. Nov.

Epiphytic on tree trunks in open forests; 1700-1800 m. SE Xizang, S and SW Yunnan [India, Myanmar, Nepal, Thailand].