Cynoctonum wilfordii Maximowicz, Melanges Biol. Bull. Phys.-Math. Acad. Imp. Sci. Saint-Petersbourg 9: 799. 1876; Seutera wilfordii (Maximowicz) Pobedimova; Vincetoxicum wilfordii (Maximowicz) Franchet & Savatier.

Roots fleshy, irregularly fusiform, up to 10 × 2 cm. Stems twining, to 2 m, pubescent along 1 line. Leaves opposite; petiole 2 cm, with adaxial glands; leaf blade ovate or ovate-cordate, 5-6 × 2-4 cm, thin papery, appressed puberulent, adaxially dark when dry, base auriculate-cordate, basal lobes rounded, recurved or incurved, apex short cuspidate to acuminate; basal veins 3-5, lateral veins ca. 4 pairs. Inflorescences umbel-like to very short racemelike, hemispherical, densely 15-20-flowered; peduncle ca. 1.5 cm, rarely dichotomous, puberulent along 1 side. Pedicel 5-7 mm, puberulent. Sepals oblong-lanceolate, ca. 1.5 × 0.6 mm, glabrous or sparsely pubescent; basal glands 10. Corolla yellowish, rotate; lobes lanceolate, 4.5-5 × ca. 2 mm, glabrous outside, densely short pilose inside. Corona deeply 5-lobed; lobes rounded to nearly square, membranous, shorter than gynostegium, base attenuate, apex truncate, with transverse adaxial ridge. Gynostegium stipitate. Anther appendages ovate, almost as long as corona; pollinia oblong. Stigma head umbonate. Follicles lanceolate, 11-12 × 1-1.4 cm. Seeds ovate, ca. 7 mm; coma ca. 2 cm. Fl. May-Sep, fr. Jul-Nov.

The root is used as medicine for impotency, neurasthenia, and lumbago.

Thickets, valleys, mountain slopes, roadsides, grasslands; 800-1500 m. Anhui, Gansu, Henan, Hubei, Hunan, Jiangsu, Liaoning, Shaanxi, Shandong, Shanxi, Sichuan, Xizang, Yunnan [Japan, Korea, Russia]