This species is infrequent and is restricted to the area shown on the map. It is found in dry, sandy or gravelly soil on knolls and ridges or in a prairie habitat in the open along roadsides or in open woodland.
Shrub 5-10 dm, erect or ascending, simple or sparingly branched, ordinarily closely canescent throughout; petioles 1-3 mm; lfls crowded, 13-20 pairs, 1-2 cm, inconspicuously or scarcely punctate; racemes usually clustered in groups of 5-20+, the terminal one 5-15 cm, the others shorter; cal-lobes lanceolate, subequal, mostly 1-1.5 mm, half to two-thirds as long as the tube; banner 4.5-6 mm; fr canescent, 4 mm; 2n=20. Dry prairies and sandy open woods; s. Mich. to Minn. and Sask., s. to Ill., Mo., Ark., Tex., and N.M. June, July. The rare hybrid with no. 4 [Amorpha fruticosa L.] is A. خotha E. J. Palmer.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.