四川牛奶菜 si chuan niu nai cai

Marsdenia balansae Costantin 1912, non Baillon 1889.

Lianas to 5 m, brownish tomentose. Stems densely lenticellate. Petiole 1-2 cm; leaf blade ovate or broadly elliptic, 5-10 × 3.5-7 cm, base rounded to shallowly cordate, tip abruptly acuminate to attenuate; lateral veins 5 pairs, flattened. Inflorescences racemelike, many flowered; peduncle 1-3 cm, rachis clearly spiral, 3-7 cm. Pedicel 1-2 mm, tomentose. Sepals ovate, 1.5 mm, hispid. Corolla tubular, slightly constricted at throat, glabrous outside; tube 1.8-3 mm, with double hair bands inside, throat with a ring of brushlike hairs; lobes ovate, 1.5-1.8 × ca. 1.5 mm. Corona lobes broadly ovate, connate at base, tips free and long acuminate, as long as anther appendages. Anther appendages long acuminate, concealing stigma head; pollinia oblong, as long as retinaculum. Gynostegium as long as corolla tube. Stigma head subovoid, apex slightly depressed. Fl. Apr.

Bushland. Sichuan, Yunnan [Laos, Vietnam].