Annual; lfls narrowly to broadly oblong or lanceolate, 3-5 cm, pilose on both sides, more densely so beneath, with stiff hairs 1-2 mm; fls 5-8 mm; cal and bracteoles hirsute, the bracteoles lanceolate, varying in length; fr 2-4 cm, spreading-hairy; seeds 2.5-3 mm, the pubescence easily detached; otherwise much like no. 1 [Strophostyles helvula (L.) Elliott]. Dry or moist sandy soil, upland woods, dunes and shores; O. to Wis. and N.D., s. to Ala. and Tex. (S. pauciflora)

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

©The New York Botanical Garden. All rights reserved. Used by permission.

From Flora of Indiana (1940) by Charles C. Deam

This species prefers a very sandy or sandy, clay soil. I have infrequently found it in a few of the southern counties. The reports from Lake, Marshall, and Putnam Counties were of specimens collected in railroad ballast and may have been introduced. The seed of all our species are mealy-pubescent. The pubescence is easily detached in this species while in the preceding species [Strophostyles umbellata] it is persistent.

……

Indiana Coefficient of Conservatism: C = 4

Wetland Indicator Status: N/A

Diagnostic Traits: annual vine with trifoliate leaves; leaflets linear to lance-ovate, unlobed, silky hairy beneath; bracteoles shorter than adjacent calyx tube; calyx 4-lobed, densely pubescent; legumes rounded, 2-5 cm, hairy.