美柱兰 mei zhu lan

Callostylis rigida subsp. discolor (Lindley) Brieger; Eria discolor Lindley; E. elongata Blume; E. pendula Ridley; E. pholidotoides Gagnepain; E. rigida H. G. Reichenbach (1857), not Blume (1856); Tylostylis discolor (Lindley) J. D. Hooker; T. rigida (Blume) Blume.

Rhizome creeping, 4-8 mm in diam., with internodes 1-2 cm and cylindric sheaths 1-1.5 cm. Pseudobulbs shiny, ± oblong-fusiform or narrowly fusiform, 6-16 × 2-3 cm, distally 4- or 5-leaved. Leaf blade glossy, suboblong or narrowly elliptic, 12-17 × 2.4-4.3 cm, leathery, base contracted into a short petiole, apex unequally bilobed. Inflorescences often 2-4, racemose, 1.5-4.5 cm, more than 10-flowered; peduncle 2.5-3.5 cm, shortly brown tomentose; floral bracts reflexed, suborbicular or broadly ovate, 3-4 mm, both surfaces shortly tomentose. Flowers greenish yellow, 1.2-1.5 cm in diam.; sepals with grayish brown hairs abaxially and sparsely white pubescent adaxially; lip brown; column foot with a dark purple callus. Dorsal sepal elliptic, 8-10 × 4-5 mm, obtuse; lateral sepals slightly shorter and broader. Petals narrowly elliptic-obovate, 7-8 × 3.5-4 mm; lip ± broadly cordate or broadly ovate, 3.5-4 × 2-3 mm, mucronate, with a cushionlike callus in basal half. Column curved forward at right angle. Capsule narrowly oblong, 3-4 cm × 6-9 mm, with 6 longitudinal ribs, ± hairy. Fl. and fr. May-Jun. 2n = 20, 40.

Epiphytic on trees in mixed forests; 600-1700 m. S Yunnan [India, Indonesia, Laos, Malaysia, Myanmar, Thailand, Vietnam].