Stemona tuberosa Lour.

The roots are used medicinally.

Vines. Roots 9--13(--30) × 1--2 cm. Stems often branched, base woody. Leaves opposite or whorled, rarely alternate; petiole 3--10 cm; leaf blade ovate to ovate-lanceolate, 6--24 × (2--)5--17 cm, membranous, veins 7--13, base cordate, margin slightly undulate, apex acuminate. Inflorescences racemes, 1--3-flowered; peduncle or pedicel axillary or rarely borne on petiole, 2.5--5(--12) cm; bracts lanceolate, 5--10 mm. Perianth segments greenish with purplish veins, 3.5--7.5 × 0.7--1 cm, apex acuminate. Stamens purple, slightly shorter than perianth; filaments stout, 2--5 mm; anthers linear, ca. 10 mm; appendages partially adherent, adaxial one ca. 5 mm. Capsule ovoid-oblong, 2.5--6 × 1--3 cm. Seeds several. Fl. Apr--Jul.

Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Hunan, Jiangxi, Sichuan, Taiwan, Yunnan [Bangladesh, Cambodia, NE India, Laos, Myanmar, Philippines, Thailand, Vietnam].

Forest margins, thickets, mountain slopes, trail sides; 300--2300 m.

Stemona acuta C. H. Wright.

Stemona tuberosa is a species of flowering plant in the family Stemonaceae. It is native to China, India, southeast Asia, and New Guinea. Hornets play an important role in seed dispersal by biting off the seed with its elaiosome and then carrying the seed away for about 100 m. There they chew off the elaiosome and abandon the seed which is likely to be taken by ants into their nest.