Marsdenia koi 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.

Guangdong, Guangxi, Guizhou, Xizang, Yunnan [Myanmar, Vietnam].

Mixed woods; 500-3200(?) m.

Marsdenia tsaiana Tsiang.

Marsdenia koi là một loài thực vật có hoa trong họ La bố ma. Loài này được Tsiang mô tả khoa học đầu tiên năm 1936.

大叶牛奶菜（学名：Marsdenia koi）是夹竹桃科牛奶菜属的植物，为中国的特有植物。分布于中国大陆的贵州、西藏、广西、广东等地，生长于海拔1,900米至3,200米的地区，常生长在山地杂木林中或溪边，目前尚未由人工引种栽培。