Stems decumbent or creeping at base, 3-8 dm; upper part of the stem, infl, sep, and both sides of the lvs glabrous to very minutely puberulent, the hairs not over 0.1 mm; lvs lanceolate, acuminate at both ends, 4-10 cm; cymes 1-10-fld, dense, subsessile in the axils of foliage lvs; sep lanceolate to ovate, 5-8 נ1.5-4 mm; cor 7-11 mm; styles and stamens ca 3.5-5 mm; fr glabrous, 5 mm thick; 2n=20. Wooded swamps; s. Ind. and se. Mo. to Ala. and Tex. June-Sept. (H. affinis; Nama a.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.