Perennial; stems tufted, branched from the base, 1-3 dm, prostrate to erect; lfls obovate, 8-15 mm, glabrous or sparsely pubescent; peduncles, pedicels and cal hirsutulous; heads globose, on peduncles to 12 cm; fls 5-6 mm; cal-tube 1 mm, the lobes unequal, the upper 2 the largest, 2.5-3.2 mm, narrowly triangular and conspicuously 3-nerved; cor purplish, the standard broadly ovate, longer than the sharply acute wings. Dry fields, open woods, and waste land; s. Va. to Fla. and Tex., n. in the interior to Mo. and Kans. Spring and summer.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.