Description from Flora of China
Herbaceous and deciduous vines, 4-5 m, glabrous. Stems and leaves containing red juice. Petiole subequal to or slightly longer than leaf blade; leaf blade soft, triangular-rounded to triangular-oblate, 5-11 cm, length subequal to or slightly longer than width, thinly papery, both surfaces glabrous, base subtruncate or slightly emarginate, apex mucronate or obtuse, entire or undulate, palmately (9 or)10-veined, raised abaxially, together with reticulation brown when dry. Inflorescences compound umbelliform cymes. Male inflorescences axillary or 2 or 3 borne on short axillary branches, slightly fleshy and slender; peduncle 2-6 cm, or longer; umbellet pedicels 4-8, up to 2.5 cm; bracts lanceolate-linear, 1.5-2.5 mm, occasionally 1-3 foliaceous, up to 1.5 cm. Male flowers: sepals 6 in 2 whorls, with purplish stripes, outer whorl smaller, obovate to oblanceolate, 1.2-1.6 mm, apex mucronate, inner whorl rhombic-cuneate, 2-2.2 × ca. 1.8 mm, base abruptly clawed below middle; petals 3, conchiform, ca. 1 × 1.8-2 mm. Female flowers and inflorescences unknown. Infructescences compound umbelliform; peduncle slightly slender, 5-7 cm; umbellet pedicels 7-11, 1-2.5 cm; fruiting pedicel not fleshy, ca. 5 mm. Drupes red; endocarp obovate-rounded, 6-7 mm.
Stephania yunnanensis is regarded as over-harvested for medicinal usage (Annex 2 of Identification and Conservation of Important Plant Areas for Medicinal Plants in the Himalaya, Plantlife).
● Limestone hills, shrublands at ditch sides. Yunnan.