1. Sanguisorba canadensis Linnaeus, Sp. Pl. 1: 117. 1753.
Canada burnet, sanguisorbe du Canada, herbe à pisser
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.
Flowering Jul–Sep; fruiting Aug–Oct. Fens, stream channels (also lower stream channels), bogs, seeps, swamps, stream shores; 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.