Antidesma scandens Loureiro, Fl. Cochinch. 1: 157. 1790; Humulopsis scandens (Loureiro) Grudzinskaja; Humulus japonicus Siebold & Zuccarini.

Plants annual. Petiole 5-10 cm; leaf blade palmately (3 or)5-9-lobed, sometimes simple, 7-10 × 7-10 cm, papery, abaxially with rigid spinulose hairs on veins, adaxially pubescent but not densely so, base cordate; lobes ovate-triangular, margin serrate. Male inflorescences 15-25 cm. Male flowers: yellowish green. Female inflorescences ca. 0.5 in diam.; bracts ovoid, 7-10 mm, papery, spinulose, apex acuminate. Female flowers: 1 per bract inflorescence; ovary included by bracts; styles exerted from bracts. Infructescences 0.5-1.5(-2) cm. Achenes exerted from bracts when mature. Fl. spring to summer, fr. autumn.

No type specimen could be found of Antidesma scandens. Merrill’s transfer of this species to Humulus is based on Loureiro’s cryptic description, and this synonymy has not been universally accepted. For this reason the species has been variously recognized as H. scandens or H. japonicus in recent treatments.

The whole plant is used medicinally and the seed oil is used to make soap.

Forest margins, wastelands, along streams. Anhui, Chongqing, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Shaanxi, Shandong, Shanxi, Sichuan, Taiwan, Xizang, Yunnan, Zhejiang [Japan, Korea, Vietnam; naturalized in Europe and E North America].