Description from Flora of China
Tropidia assamica Blume; T. formosana Rolfe; T. graminea Blume; T. hongkongensis Rolfe; T. squamata Blume.
Plants 30-70 cm or taller. Rhizome short, rigid; roots 2-3 mm in diam., fleshy. Stem erect, unbranched or occasionally with branches, proximally often naked, distally enclosed in leaf sheaths, internodes 2-4 cm. Leaves many, often more than 10, distichous and well spaced along stem, narrowly elliptic-lanceolate to narrowly lanceolate, (10-)15-25 × (1-)2-4 cm, papery, base contracted into amplexicaul sheath, apex long acuminate-caudate. Inflorescence racemose, terminal or axillary, with several to 10 crowded flowers, 1-2.5 cm; floral bracts imbricate, lanceolate, 4-7(-10) mm, conspicuously with longitudinal veins. Flowers not resupinate, greenish white; pedicel and ovary 5-6 mm. Sepals lanceolate or oblong-lanceolate, 7-10 × 1.5-1.7 mm, apex long acuminate; lateral sepals connate only at base, apex recurved. Petals oblong-lanceolate, 6-8 × ca. 1.3 mm; lip ovate-lanceolate or oblong-lanceolate, cymbiform, 6-8 mm, concave-saccate at base, with 2 inconspicuous lamellae on disk, apex acuminate. Column ca. 3 mm; anther ovoid, ca. 1.5 mm; rostellum erect, obovate, ca. 2 mm, apex 2-lobed-apiculate. Capsule suboblong, ca. 2 cm × 5 mm. Fl. Jun-Aug, fr. Oct. 2n = 40, 60.
Shaded places, along valleys in forests; 200-1000 m. SW Guangxi, Hainan, Hong Kong, Taiwan, SE Xizang, S and SE Yunnan [Cambodia, India, Indonesia, Malaysia, Myanmar, Thailand, Vietnam].