Aerial shoots (15-)20-80 cm, from caudices on rhizomes, caudices ascending, rhizomes ascending to horizontal. Basal leaves 1-5, simple, deeply divided; petiole 8-22(-37) cm; leaf blade orbiculate, 4-10 × 5-15(-20) cm, base sagittate to nearly truncate, margins serrate and incised on distal 1/3-1/2, apex acuminate, surfaces puberulous (more so abaxially); segments primarily 3, lanceolate to oblanceolate; lateral segments again 1×-lobed or -parted (proximal lobe occasionally lobed again); ultimate segments 10-30(-35) mm wide. Inflorescences 1(-3+)-flowered, rarely cymes; peduncle puberulous to villous, distally densely villous; involucral bracts 3 (secondary involucres with 2), remotely subtending flowers, (1-)2-tiered, simple, ±similar to basal leaves, broadly obtriangular, 3-cleft, 3-10 cm, bases broadly cuneate, connate, margins sharply, irregularly serrate and incised on distal 1/3-1/2, apex acuminate, surfaces puberulous, more so abaxially; segments 3, lanceolate to oblanceolate; lateral segments unlobed or 1×-lobed; ultimate lobes (8-)10-15(-20) mm wide. Flowers: sepals (4-)5(-6), white, obovate, (8-)10-20(-25) × 5-15 mm, hairy or glabrous; stamens 80-100. Heads of achenes spheric to ovoid; pedicel 7.5-11.5 cm. Achenes: body obovoid to ellipsoid, (2.5-)3-6 × 3.5-6 mm, winged, strigose or glabrate; beak straight, 2-6 mm, strigose, not plumose. 2 n =14. Flowering spring-summer (May-Aug). Damp thickets, meadows, wet prairies, lake shores, streamsides, clearings, occasionally swampy areas; 200-2800 m; Alta., B.C., Man., N.B., Nfld., N.W.T., N.S., Ont., P.E.I., Que., Sask.; Colo., Conn., Ill., Ind., Iowa, Kans., Maine, Md., Mass., Mich., Minn., Mo., Mont., Nebr., N.H., N.J., N.Mex., N.Y., N.Dak., Ohio, Pa., S.Dak., Vt., W.Va., Wis., Wyo. Various parts of Anemone canadensis were used medicinally by Native Americans in the treatment of wounds, nasal hemorrhages, eye problems, and sore throats, to counteract witch medicines, and as a general panacea (D. E. Moerman 1986).
Rhizomatous perennial, 2-8 dm; basal lvs long-petioled, rotund, deeply 3-parted, the segments more or less cleft and sharply toothed; involucral lvs similar but sessile; peduncles 1-3, the lateral ones commonly with a small secondary involucre; sep 5, white, mostly 12-20 mm long; achenes flat, suborbicular, 3-5 mm, strigose; style 2-5 mm, strigose; 2n=14. Sandy shores, damp prairies, and wet meadows, abundant; e. Que. to Alta., s. to Md., W.Va., Ky., Mo., and N.M. May-Aug.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.