Bracts and uppermost lvs lanceolate, glabrous, acute; cor white, 3-4 mm; fr sharply triangular in cross-section, the fertile locule flat on the back, much wider than the 2 sterile ones, which are barely separated by a short pit near the center. S. Ont. to Wis., s. to Pa. and Ind. May, June.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.