Lvs usually oblong or obovate- oblong, often twice as long as wide, cal-lobes hirsutulous at the tip, otherwise glabrous; cor conic in bud, gradually acute to acuminate, scarcely twisted, at anthesis brownish-purple to greenish-purple, its lobes narrowly lanceolate, 8-14 mm, thrice as long as the cal; corona nearly rotate, much shorter than the gynostegium; pollen-sacs inconspicuous, with narrow slits, the pollinia ±pendulous; fr glabrous, 8-13 mm, sharply angled but not winged. Moist woods and thickets; se. Va. to Fla. and Tex., and up the Mississippi embayment to s. Mo. and s. Ind. July. (Gonolobus g.; Vincetoxicum g.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.