Stems clustered on a taproot, ±erect, 3-9 dm, branching, usually hollow, glabrous or nearly so, amply leafy; stipules free; lfls 11-23, oblong to elliptic or obovate, 1-3 cm, strigose beneath; racemes several, each scarcely surpassing the subtending lf, with 10-20 white or chloroleucous fls 11-15 mm; cal-tube cylindric, 4-5 mm, the lobes half as long; fr erect, sessile, straight, fusiform or obliquely ovoid, inflated, 1.5-2 cm נ8-18 mm, glabrous, the sutures scarcely sulcate; 2n=22. River-banks and lake-shores, especially on limestone; irregularly from c. N.Y. and se. Ont. to Sask.; N.D., and S.D.; Grant Co., W.Va., and Alleghany Co., Va. June. (A. cooperi; Phaca n.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
