Erect, glabrous perennial 4-15 dm, much branched above; lvs mostly opposite, narrowed to a sessile base, mostly shorter than the internodes, the lower linear-oblong, 1-4 cm, to 4 mm wide, the upper smaller, those subtending the fls linear, mostly 8-15 mm; fls axillary, heterostylic as in no. 2 [Lythrum alatum Pursh], short-pedicellate; hypanthium 4 mm; appendages triangular, about equaling the sep; pet pale purple to white, 3-4 mm; 2n=20. Brackish marshes on the coastal plain; N.J. to Fla. and La. July-Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.