Description from Flora of China
Pontederia crassipes Martius, Nov. Gen. Sp. Pl. 1: 9. 1823; Eichhornia speciosa Kunth; Heteranthera formosa Miquel.
Herbs floating, 0.3--2 m. Roots many, long, fibrous. Stems very short; stolons greenish or purplish, long, apically producing new plants. Leaves radical, rosulate; petiole yellowish green to greenish, 10--40 cm, spongy, usually very much swollen at or below middle; leaf blade orbicular, broadly ovate, or rhomboidal, 4.5--14.5 × 5--14 cm, leathery, glabrous, densely veined, base shallowly cordate, rounded, or broadly cuneate. Inflorescences bracteate, spirally 7--15-flowered; peduncle 35--45 cm. Perianth 6-parted, segments purplish blue, petaloid, ovate to elliptic, upper one larger with yellow blotch at center adaxially, others subequal but lower one narrower. Stamens 6, 3 long and 3 short; filaments curved, glandular hairy. Pistil heterostylic; stigma glandular hairy. Capsule ovoid. Fl. Jul--Oct, fr. Aug--Nov.
The entire plant is used for fattening livestock, and as green manure. The young leaves and petioles are sometimes used as a vegetable.
Naturalized, growing gregariously in pools, ditches, and rice fields; 200--500 m. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hebei, Henan, Hubei, Hunan, Jiangsu, Jiangxi, S Shaanxi, Shandong, Sichuan, Taiwan, Yunnan, Zhejiang [native to Brazil; widely introduced and naturalized in tropics and subtropics].