Rhizome short and freely rooting; stems slender, to 1 m, laxly and diffusely branched, soon becoming prostrate or spreading and often rooting; nodes usually with a fringe of short hairs; lvs lanceolate or lance-ovate, the larger ones 4-10 נ1-2.5 cm, scabrous on the margin, broadly acute to rounded at base, on long, eciliate petioles; cal-lobes and cor-lobes 3-5 mm; stamens distinct; staminodes triangular-subulate, obtuse; fr equaling or exceeding the cal; 2n=34. Swamps and wet soil, usually in shade; e. and c. Va.; Mo. and s. Ill. to e. Tex. and w. Fla. June-Aug. (Steironema r.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.