Rhizomes 3-4 mm in diam., producing from near base of pseudobulb, each section 2-3 cm long. Pseudobulbs cylindrical-conic, 4-7 cm long, 3-5 mm in diam., slightly dilated at base, enclosed by sheaths. Leaves solitary or rarely with an additional small one, elliptic or ovate, 10-18 cm long, 5-8 cm wide, apex acute, obtuse to nearly cordate at base, plicate, sometimes with dark spots on upper surface of old leaves; petiole, ca. 1 cm long. Peduncle arising from base of pseudobulb, ca. 15 cm long, with 2 tubular sheath below, rachis 5-7 cm long; bracts ovate-lanceolate, 7-10 mm long; pedicel and ovary ca. 10-13 cm long. Flower 3-6, perianth not opening widely, with green sepals and petals; dorsal sepal narrowly oblong or lanceolate oblong, 10-12 mm long, 2.5-3 mm wide, apex acute, slightly contracted at base; lateral sepals lanceolate oblong, 10-12 mm long, 3 mm wide, apex acuminate, base not contracted and adnate to column foot forming mentum ca. 6-7 mm long; petals similar to dorsal sepal but slightly oblique; lip yellowish white, with red spots, cuneate-obovate, ca. 12 mm long, 9 mm wide, clawed at base, 3-lobed, lateral lobes erect, semiorbicular or ovate, nearly entire, disc with 2 elevated keels, keels higher at middle, lowered and convergent toward base but not forming close tube; column yellowish white, 7-9 mm long, 2 mm wide, with 2 acute wing near tip; anther cordate, 1.5 mm long, glabrous; pollinia angular, ovate, 1.2 mm long, free or connected by vicid material.

TAIPEI: Wulai, Su & Chung 8499*.

Southern China (Kwangtung, Hainan and Yunnan), Vietnam and Thailand. Taiwan, only recorded from northern part of this island, forests below 700 m, rather rare.

The present species is similar to C. formosanum, although with larger leaves and smaller flowers. However, it can be distinguished from the latter by vegetative and floral structures as listed in above key. In northern Taiwan, it flowers in early September, while the latter flowers from May to July.