Local on the crests of a few chestnut oak ridges of the southern part of the state. I have, however, a specimen from very sandy soil in a low depression in a very sandy woods on the Herschel Green farm about 4 miles north of Washington, Daviess County. This depression is a small prairie of about 3 acres surrounded by red birch and pin oak. In the "flats" are a number of plants of the Coastal Plain. The reports from Kosciusko and Putnam Counties, no doubt, should be referred to some other species.
Stems twining, usually climbing, to 1.5 m; stem, cal, and at least the lower surface of the lfls loosely spreading-hairy; lfls commonly ovate or ovate-oblong, varying to narrowly oblong; racemes often 1 dm, loose, the fls well separated by internodes often 1-3 cm; fls 7-10 mm; cal-lobes 2-4 mm; fr 2-4 cm, shortly and densely spreading-hairy; 2n=20. Dry upland woods and barrens; s. N.Y. to s. O., Mo., and Kans., s. to Fla. and Tex. July, Aug. (G. regularis, probably misapplied) Plants occurring mainly in the Mississippi Valley region, with the lfls loosely hairy on the upper as well as the lower surface, may warrant recognition as var. mississippiensis Vail (G. mississippiensis).
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.