Herbs , 15-120 cm, mostly pubescent when young, often glabrate, having rhizomes, often with adventitious roots. Leaves 4-25 cm; petiole 1-10 cm; blade ovate, 2-17 × 1-10 cm, base cordate, apex acuminate. Racemes nodding to erect, fragrant, narrow, 5-35 cm. Floral bracts green, boat-shaped, 1.5-3 mm (distinct portion), adnate to pedicel. Schizocarps brown, 1.5-3 mm, rugose. Seed brown, 1-1.3 × 0.7-1 mm, smooth. 2 n = 22. Flowering spring-summer, sometimes early fall. Wet soil, fresh or slightly brackish water to depth of 5 dm; 0-500 m; Ont., Que.; Ala., Ark., Conn., Del., Fla., Ga., Ill., Ind., Kans., Ky., La., Md., Mich., Miss., Mo., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., S.C., Tenn., Tex., Va., W.Va. Some American Indians used Saururus cernuus for medicinal purposes (D. E. Moerman 1986).
From Flora of Indiana (1940) by Charles C. Deam
Infrequent to frequent throughout the state in wet woodland, along muddy borders of streams, and about ponds and sloughs. Where it is found it usually forms almost a complete stand over the area.
Branched, 5-12 dm; lvs with long, basally sheathing petiole, the blade cordate-ovate, 6-15 cm; spikes 1 or 2, peduncled, terminal but often surpassed by axillary branches, 6-15 cm, nodding at the tip before anthesis; filaments white, 3-4 mm, much surpassing the pistils; fr 2-3 mm thick; 2n=22. Swamps and marshes; s. N. Engl. and s. Que. to Minn., s. to Fla. and Tex. June-Aug.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.