Stout annual to 2.5 m, the stem 4-angled, somewhat scabrous-hairy above; lvs elliptic to linear-elliptic or lanceolate, tapering to a subsessile or petiolar base, sharply serrate or incised, at least above the middle, strigillose above, sparsely hairy beneath; spikes compact, mostly short, usually sessile in open cymes, not crowded; bracts scarcely equaling the cal, lance-subulate, ciliate; cal 3-4 mm; cor purple or lilac, its tube a little longer than the cal, hairy outside, the inconspicuous limb 2.5 mm wide; nutlets 1.5-2 mm; 2n=28. Native of S. Amer., intr. in dry sandy soil and waste places from Va. to Fla. and La. Mostly Apr.-Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
