Description from Flora of China
Pentasachme stauntonii Decaisne in A. de Candolle, Prodr. 8: 627. 1844; Cynanchum linearifolium Hemsley; Pentasachme brachyantha Handel-Mazzetti; Vincetoxicum linearifolium (Hemsley) Kuntze; V. stauntonii (Decaisne) C. Y. Wu & D. Z. Li.
Herbs glabrous except for corolla and sometimes interpetiolar lines. Roots fascicled, slender. Stems erect, to 1 m. Leaves opposite; petiole ca. 5 mm; leaf blade narrowly lanceolate, 6-13 cm × 3-9(-17) mm, papery, acuminate at both ends; lateral veins ca. 6 pairs. Inflorescences slender, racemelike; peduncle up to 1.7 cm. Pedicel 3-9 mm. Sepals ovate-oblong, 1-1.5 × 0.4-0.5 mm; basal glands few. Corolla purple, less often greenish yellow, rotate; tube ca. 1.5 mm; lobes linear-oblong, 3-5(-8) × 0.6-1 mm, obtuse, interior minutely and conspicuously villous at base, sometimes throughout. Corona lobes 5, ovate, pouched, blunt, adaxially keeled, shorter than anthers and adnate to them at base. Anther appendages rounded, covering stigma head; pollinia oblong. Stigma head convex, included. Follicles linear-lanceolate in outline, 9-12 cm × 3-6 mm, smooth, glabrous. Seeds oblong; coma ca. 2.5 cm. Fl. May-Aug, fr. Sep-Dec.
Decoctions of all parts are used as a febrifuge and for treating internal fever. The roots are used medicinally for pulmonary tuberculosis, infantile malnutrition due to intestinal parasites, influenza, cough, and chronic bronchitis.
Cynanchum stauntonii is somtimes confused with Pentasachme caudatum, which is similar in habit and grows in similar habitats, but the latter can easily be distinguished by the longer,
white, glabrous corollas.
* Sunny places in moist woodland, water-logged lands; low to medium elevations. Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hunan, Jiangsu, Jiangxi, Yunnan, Zhejiang