Sp. Pl. 1: 117. 1753.
Plants 9–20 dm. Leaves: blade 5–55 cm, leaflets 7–17, oblong-ovate to lance-oblong, 10 × 4 cm, lengths ca. 2–4 times widths, base broadly cuneate, truncate, or rounded to slightly cordate, sometimes with leafy stipels (especially on vigorous basal leaves). Spikes 250–500+-flowered, cylindric, main 10–25 cm, flowering acropetal. Flowers: calyx lobes white to greenish white, midveins thickened distally; stamen lengths 4–6 times calyx lobes, filaments 6–10 mm, distally flattened-clavate. 2n = 56.
Phenology: Flowering Jul–Sep; fruiting Aug–Oct.
Habitat: Fens, stream channels (also lower stream channels), bogs, seeps, swamps, stream shores
Elevation: 0–1600 m
St. Pierre and Miquelon, N.B., Nfld. and Labr., N.S., Que., Conn., Del., D.C., Ga., Ill., Ind., Ky., Maine, Md., Mass., Mich., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Tenn., Vt., Va., W.Va.
Reports of Sanguisorba canadensis for Manitoba seem biogeographically unlikely and no definite documentation has been found; they are rejected pending additional information.