Much like no. 8 [Epilobium ciliatum Raf.]; erect, to 1 m, usually freely branched, ±pubescent, especially above, with short, incurved hairs, the pubescence of the stem tending to be in lines; lvs chiefly opposite, narrowly lanceolate or oblong-lanceolate, the larger often 1 dm, sharply and irregularly serrate with numerous (4-8 per cm of margin) teeth; fls numerous; cal-teeth free at the tip in bud, projecting; pet 4-5 mm, pink or white; fr 3-5 cm; seeds abruptly rounded and beakless at the summit; coma brown; 2n=36. Wet soil; Me. to Minn., s. to N.C., Ala., Ark., and Tex. July-Oct. A hybrid with no 8 has been called E. طisconsinense Ugent.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Frequent throughout the state except in the southern counties. In wet soil in roadside and dredged ditches and wet woods, and on the borders of lakes, ponds, and streams.