Stems climbing or trailing to 8 m, pubescent; petioles pubescent, glandular at or near the summit; lvs deeply 3-lobed, puberulent beneath, truncate or rounded to a small cuneate base, the lobes lance-ovate, constricted at base, acuminate, serrulate; peduncle elongate, with glandular-serrate bracts above; fls 4-6 cm wide, the pet and sep white, the outer corona 2 cm, purple or pink, the inner much shorter; berry edible, yellow, ellipsoid, 5 cm; 2n=18, 36. Fields, roadsides, thickets, and open woods; Va. and sw. Pa. to s. O., s. Ill. and Okla., s. to Fla. and Tex. June-Aug.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Very rare. It is locally common, however, on the rocky open slope of the Ohio River about midway between Cannelton and Tell City. I saw it in Crawford County near Wyandotte Cave but I was not prepared to preserve a specimen. I have it from two places along the Ohio River above Cannelton in Perry County and from one place along the Ohio River about 3 miles above Mauckport in Harrison County. Charles M. Ek found a large colony in hard, clay soil along a railroad embankment a quarter of a mile north of Galveston, Cass County.