Erect, freely branching glabrous annual to 2 m, the stem 4- angled and commonly 4-winged by the decurrent lf-bases; lvs alternate, lanceolate to linear, sessile or nearly so, the main ones mostly 5-12 נ1-3.5 cm; pedicels 1-5 mm; fls tetramerous; ovary at anthesis obconic, 4-angled, 8-10 mm; pet 8-12 mm; stamens 8; fr slenderly pyramidal, 4-angled or narrowly 4-winged, 1-2 cm; seeds multiseriate in each locule, ellipsoid, 0.3-0.4 mm; 2n=16. Swamps and shallow water, chiefly on the coastal plain; Md. to Fla. and Tex., n. in the interior to s. Ind. and s. Mo., and s. to Argentina. July-Sept. (Jussiaea d.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
In very wet, sandy soil in the outlet of a spring about 10 miles southwest of Mt. Vernon in Posey County, and on a sandy bar in a small stream in a woods about 4 miles southeast of Hatfield, Spencer County.