Tree to 25 m, the twigs and peduncles puberulent, becoming subglabrous; stipules commonly modified into spines 1 cm; lfls 7-19, oval or elliptic, 2-4 cm; racemes drooping, many-fld, 1-2 dm; fls white, fragrant, 1.5-2.5 cm; cal finely hairy, the upper lip truncate or broadly notched; ovary glabrous; fr 5-10 cm; 2n=20. Native from Pa. and s. Ind. to Okla., s. to Ga. and Ala., and often escaped from cult. n. to N.S. and Que. May, June.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.