Frequent to common in all parts of the state. Less frequent in the less calcareous soils. Usually in moist soil along roadsides and railroads, often common in cultivated fields, especially oatfields, and in fallow fields and open woodland. This species is variable as to width and shape of the leaves and the density and length of the tubercles on the follicles.
Colonial by roots; stems stout, 1-2 m, mostly simple, hairy; lvs thick, narrowly or broadly elliptic to ovate or oblong, 10-15 cm, acute or apiculate, soft-hairy beneath; petioles 5-15 mm; umbels often numerous, terminal and lateral, compactly many-fld; peduncles 3-10 cm; cor nearly purple to nearly green, its lobes 7-10 mm; hoods pale purple, somewhat divergent, 4-5 mm, surpassing the gynostegium, the lateral margins with a prominent, sharp, triangular lobe near the middle; horns short, inflexed; fr erect on deflexed pedicels, 7-12 cm, tomentose and beset with soft, filiform to conic processes; 2n=22. Fields, meadows, and roadsides; N.B. to Va. and n. Ga., w. to Man., Nebr., and Okla. June-Aug. (A. kansana) Native, the specific epithet in error.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.