General: Perennial, 30-120 cm tall; stems few, erect to ascending, leafy; herbage and inflorescence stiffly hirsute; caudex thick, scaly, rarely branched; roots fibrous. Leaves: Basal and cauline, alternate, basal blades pinnately divided or dissected, 8-30 cm long, leaflets approximately 5-9, the terminal leaflet cordate or rounded at base, many times larger than the adjacent lateral ones, ultimate margins coarsely once- or twice- toothed, cauline blades similar, smaller, mostly trifoliate, the leaflets oblanceolate, margins serrate; stipules leaf-like, 6-18 mm long, margins irregularly cleft to toothed; basal blades long-petiolate, cauline blades shortly petiolate. Flowers: Inflorescence a cyme, 2-15 flowered, borne on a scape 2- 15 cm long, usually surpassed by the leaves; hypanthium, bractlets, and sepals sparsely to densely silky-villous; bractlets lanceolate, 3-6.5 mm long; sepals spreading to ascending in fruit, lanceolate, 4-8 mm long, apex acuminate; petals broadly obovate, 5-12 mm long, white to sometimes pinkish; stamens 20; pistils numerous; flowers June-July. Fruits: Achene, numerous, ovoid-elliptic, 2.2-3.2 mm long, flattened, villous; style jointed, the persistent lower portion 2.7-5.7 mm long, glandular-puberulent, hooked at the tip, the deciduous upper portion 1-1.7 mm long, hirsute in the upper half. Ecology: Meadows, streambanks, shaded habitats; 1700-2900 m (5500- 9500 ft); Apache, Cochise, Coconino, and Graham counties; Canada, northeastern, north-central, western, and southwestern U.S. Notes: Ours is var. perincisum. Geum aleppicum (yellow avens) [=Geum strictum] is very similar but is distinguished by the terminal leaflet of basal leaves being only slightly larger than adjacent lateral leaflets and the base wedge- shaped; and the lower persistent portion of jointed style is hirsute at the base. It occurs in similar habitats. Editor: Springer et al. 2008
Stem to 1 m, hirsute, especially below; basal lvs long- petioled, the terminal segment rotund to reniform, 5-12 cm wide, often 3-lobed, the lateral few, much smaller, interspersed with several to many minute lfls; upper lvs short-petioled to sessile, deeply 3-lobed or 3-foliolate; pet yellow, 4-7 mm, somewhat exceeding the sep; achenes minutely pubescent throughout, hirsute about the summit; basal segment of the style minutely glandular, the terminal segment minutely pubescent; 2n=42. Moist woods and rocky ledges, sometimes weedy; Nf. and Lab. to Alas. and e. Asia, s. to Me., Vt., N.Y., Mich., Minn., and Calif. May-July. Var. perincisum (Rydb.) Raup, occurring from n. Mich. w. and n., has relatively strongly dissected lvs, the terminal lfl of the middle cauline ones 3-cleft nearly to the base with the lobes again cleft or laciniate. (G. oregonense) The widespread var. macrophyllum has less dissected lvs, the terminal lfl of the middle cauline ones 3-cleft to about the middle with the lobes merely toothed.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.