Aerial shoots 5-19 cm, from rhizomes, rhizomes ascending to horizontal. Basal leaves 3-15, often purplish abaxially, simple, deeply divided; petiole 3-19 cm; leaf blade widely orbiculate, 1.3-8 × 1.8- -11.5 cm, base cordate, margins entire, apex acute or acuminate, surfaces strongly villous to glabrescent; lobes 3(-5), deltate, 0.7-4 cm wide; middle lobe 70-90% of total blade length. Inflorescences 1-flowered, villous to pilose; involucral bracts 3, 1-tiered, simple, dissimilar to basal leaves, lanceolate to ovate, 0.53-1.8 × 0.27-0.95 cm, sessile, calyx-like, closely subtending flowers, bases distinct, cuneate, margins entire, apex acute, strongly villous to glabrescent. Flowers: sepals 5-12, white to pink or bluish, ovate to obovate, 6-14.6 × 2.2-5.8 mm, glabrous; petals absent; stamens 10-30. Heads of achenes spheric; pedicel 0.1-0.4 cm. Achenes: body narrowly ovoid, 3.5-4.7 × 1.3-1.9 mm, slightly winged, hispid, gradually tapering; beak indistinct. 2 n =14. Flowering spring. Deciduous woods, often in calcareous soils; 0-1200 m; Ont., Que.; Ala., Ark., Conn., Ga., Ill., Ind., Iowa, Ky., Maine, Md., Mass., Mich., Minn., Mo., N.H., N.Y., N.C., Ohio, Pa., S.C., Tenn., Vt., Va., W.Va., Wis. In North America, Anemone acutiloba and A . americana are sufficiently well differentiated to enable the distinction of the two species. Some intermediates do occur but it is uncertain as to whether these are true intermediates or hybrids. The fact that the two species are highly sympatric and still maintain their differences implies that they should still be recognized as distinctive species (see G.L. Stebbins 1993).
Much like H. americana and hybridizing, but maintaining its identity; lvs 3-lobed or occasionally 5-7-lobed, deeply cordate at the base, the lobes broad, acute; length of the lf blade about 3 times the distance from the summit of the petiole to the sinuses; bracts acute, about equaling the sep. Similar habitats; Que. to Minn., s. to Ga., Ala., and Mo. Mar., Apr. (H. nobilis var. acuta)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.