?Aristolochia longilingua C. Y. Cheng & W. Yu; A. triangulifolia W. Yu.

Herbs twining; roots linear or terete. Stems terete, striate, glabrous; branchlets and petiole with red juice when broken. Petiole 2-10 cm, glabrous; leaf blade ovate-cordate, 3-15 × 3-16 cm, papery, densely punctate, both surfaces glabrous, rarely abaxially pubescent, veins palmate, 3 pairs from base, often red when dry, base cordate, sinus 2-4 cm deep, apex obtuse. Flowers axillary, solitary or paired. Peduncle ascending, 1-2 cm, glabrous; bractlets ovate, 3-8 × 2-4 mm, inserted near base of peduncle. Calyx dark purple; tube rectilinear, abaxially glabrous; utricle globose, ca. 5 mm in diam., sessile; tube 4-5 × 1-2 mm; limb unilateral, ligulate, ovate-oblong, 0.8-1 × 0.4-0.5 cm, apex obtuse or emarginate and apiculate. Anthers elliptic, 0.3-0.4 mm. Gynostemium 6-lobed. Capsule cylindric, ca. 2.5 × 1.5 cm, dehiscing acropetally. Seeds ovoid or ovoid-deltoid, ca. 4 × 3.5 mm. Fl. Apr-Aug, fr. Oct-Dec.

Aristolochia longilingua is included here on the basis of the protologue; further research is needed to clarify its position and status.

This species is a well-known medicine for the treatment of snake bites.

* Forests, moist mountain slopes; 100-1700 m. Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Henan, Hubei, Hunan, Jiangxi, Sichuan, Zhejiang.