Herbs, annual, with long-trailing, decumbent shoots. Leaves: blade linear-oblong to linear-lanceolate, 1.5--7 ´ 0.2--1 cm, glabrous. Inflorescences terminal and in distal leaf axils; cymes 1-several, 1-flowered, solitary or fascicled. Flowers bisexual, radially symmetric, 1 cm wide; sepals 5--6 mm; petals purplish lilac or purple to pink or white, 5--8 mm; stamens 3; filaments bearded; staminodes 3. Capsules (4--)5--9 mm. Seeds 2--6 per locule, 1.6--3 mm, faintly ribbed. Flowering fall. Roadside ditches and swales, margins of lakes, creeks, rivers, swamps, bogs, swamp forest, and other aquatic habitats, often growing in water; introduced; Ark., Fla., Ga., Ky., La., Md., Miss., N.C., Oreg., S.C., Tenn., Va., Wash.; Europe; native, Asia. I agree with C. P. Dunn and R. R. Sharitz (1990) that this species is still expanding its range since its introduction early this century.
Stems weak, decumbent or prostrate at base, 3-8 dm; lvs lance-linear, 3-6 cm; fls solitary, the pedicels arising from one to several of the upper sheaths, or some of them in 2-4-fld axillary racemes; sep 5-6 mm; pet pink, ca 8 mm. Fresh tidal marshes and margins of lakes and ponds; native to e. Asia, intr. from Md. to Fla., and inland to Ky., Tenn., and Ark. Late summer and fall. (Aneilema k.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.