Description from Flora of China
Callista parishii (H. G. Reichenbach) Kuntze; Dendrobium polyphlebium H. G. Reichenbach.
Stems ascending or pendulous, cylindric, usually 10-30 cm or longer, stout, 1-1.3 cm in diam., upper part ± curved, unbranched, with several nodes, internodes to 4 cm. Leaves narrowly oblong, 7.5-12.5 × 1.6-1.9 cm, leathery, apex obtuse and unequally bilobed; leaf sheath white, membranous. Inflorescence lateral on old leafless stem, 1-3-flowered; peduncle 3-5 mm; basal sheaths 3 or 4, overlapping, short; floral bracts ovate-lanceolate, ca. 7 mm, acute. Pedicel and ovary 4-5 cm. Flowers spreading, large, thin, purplish red, disk with a deep purple blotch on either side, column white, anther cap purple. Dorsal sepal obovate-lanceolate, ca. 27 × 7 mm, 5-veined, apex obtuse; lateral sepals ovate-lanceolate, ca. as long as dorsal sepal and slightly narrower, 5-veined, apex acuminate; mentum narrowly conic, ca. 6 mm, obtuse. Petals broadly elliptic, slightly shorter but much wider than sepals, 5-veined, base shortly clawed, margin ciliate or denticulate, apex acute; lip rhombic-orbicular, ca. 20 × 16 mm, both surfaces densely pilose, shortly clawed, claw with a raised notched ridge on front, both sides embracing column below middle, margin densely ciliate, apex acute. Column ca. 7 mm; anther cap conic, surface papillate, front margin irregularly denticulate.
Guizhou (Xingyi), SE Yunnan (Wenshan) [NE India, Laos, Myanmar, Thailand, Vietnam].