Brasenia purpurea Caspary.

Stems to 1--2 m, glabrous, base rhizomatous. Petiole 25--40 cm; leaf blade 5--10 × 3.5--6 cm, glabrous. Flowers 1--2 cm in diam.; peduncle 6--10 cm. Perianth dull purple; segments 10--15(--20) × 2--7 mm; petals slightly longer and narrower than sepals, apex obtuse. Stamens 1/2 as long as petals, anthers linear, ca. 4 mm. Fruit 6--10 mm. Seeds 1--2, 2.5--4 × 2--3 mm. Fl. Jun., fr. Oct. 2n = 72, 80.

In ponds, lakes, or swamps. Anhui, Hunan, Jiangsu, Jiangxi, Sichuan, Taiwan, Yunnan, Zhejiang [India, Japan, Korea, Russia (Far East); Africa, Australia, North America, South America].