Erect, rhizomatous perennial, 3-6 dm; lvs 3-6 cm, oblong to ovate-oblong or elliptic, 2-3(-4) times as long as wide, rounded or retuse above, cordate or subcordate at the sessile base, dark-punctate beneath, dotted with translucent glands; sep lanceolate, acute or acuminate, 5-8 mm; pet 8-10 mm; fr trilocular, cylindric, 8-12 mm, gradually tapering to the 2-3 mm styles; 2n=38. Bogs, marshes, and wet shores; N.S. to Fla. and Miss., mostly near the coast, or inland at low altitudes across N.Y. to s. Ont., O., and the s. end of Lake Michigan. July, Aug. (Hypericum v.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.