Shrub or small tree to 10 m, with glabrous twigs; lvs oblanceolate to narrowly obovate, 3-7 cm, rounded or obtuse at the tip, finely crenulate, narrowly cuneate at base, glabrous above, pubescent at least along the midvein beneath; fls in small peduncled fascicles, often on dwarf branches, 4-5-merous; sep entire; fr red; nutlets grooved on the back; 2n=40. Swamps and wet woods, chiefly on the coastal plain; D.C. to Fla. and Tex., n. in the interior to s. Ind., s. Ill., and s. Mo. May. (I. longipes)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.