大叶牛奶菜 da ye niu nai cai

Marsdenia tsaiana Tsiang.

Lianas stout, to 15 m, glabrous except for flowers. Stems and branches pale gray, hollow when dry. Petiole 3-10 cm; leaf blade broadly ovate to ovate-oblong, 8-20 × 5.5-10 cm, papery, base cordate, apex acute and mucronate; lateral veins 5-7 pairs, flattened. Inflorescences umbel-like to short branched, shorter than leaves; peduncle 7-9 cm. Pedicel 2-4 cm. Sepals suborbicular, (3-)8 × (2.5-)6 mm, ciliate; glands 10. Corolla subcampanulate, ca. 2.8 cm wide, glabrous outside, pubescent inside; tube ca. 1.1 × 1 cm; lobes broadly ovate, ca. 1.2 × 0.9 cm, margin usually reflexed and ciliate. Corona lobes ovate-lanceolate, base turgid, with a pair of longitudinal grooves defining a blunt dorsal wing, shorter than anthers. Anthers laterally compressed, appendages rounded; pollinia reniform. Stigma head conical, apex obtusely acute and 2-cleft. Follicles ellipsoid, 5-10 × 2.5-4 cm. Seeds ovate-oblong, ca. 1.5 cm × 7 mm; coma ca. 2.5 cm. Fl. Jul-Nov.

Mixed woods; 500-3200(?) m. Guangdong, Guangxi, Guizhou, Xizang, Yunnan [Myanmar, Vietnam].