Much like no. 3 [Matelea carolinensis (Jacq.) Woodson ]; fl-buds conic; cor-lobes more ascending, 11-18 mm, a fourth or a third as wide, usually widest well above the middle. Open woods and thickets; s. U.S., n. in the interior to s. Ill. and Mo. May, June. (Gonolobus d.; Odontostephana d.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.