Britton, Trans. New York Acad. Sci. 12: 3. 1892.
Renoncule de Macoun
(A. Gray) K. C. Davis
Stems prostrate to nearly erect, often rooting nodally, hirsute or glabrous, base not bulbous. Roots never tuberous. Basal leaf blades cordate to reniform in outline, 3-foliolate, 3.7-7.5 × 4.5-9.5 cm, leaflets 3-lobed or -parted, ultimate segments elliptic or lance-elliptic, margins toothed or lobulate, apex acute to broadly acute. Flowers: receptacle hirsute; sepals spreading or reflexed ca. 1 mm above base, 4-6 × 1.5-3 mm, glabrous or hirsute; petals 5, yellow, 4-6 × 3.5-5 mm. Heads of achenes globose or ovoid, 7-11 × 7-10 mm; achenes 2.4-3 × 2-2.4 mm, glabrous, margin forming narrow rib 0.1-0.2 mm wide; beak persistent, lanceolate to broadly lanceolate, straight or nearly so, 1-1.2 mm. 2 n = 32, 48.
Flowering spring-summer (May-Sep). Meadows, depressions in woodlands, ditches, edges of streams and ponds, on wet soil or emergent from shallow water; 0-2900 m; Alta., B.C., Man., Nfld., N.W.T., Ont., Que., Sask., Yukon; Alaska, Ariz., Calif., Colo., Idaho, Mich., Minn., Mont., Nebr., Nev., N.Mex., N.Dak., Oreg., S.Dak., Utah, Wash., Wyo.
Through most of its range, Ranunculus macounii has conspicuously hispid herbage. Glabrous plants are found, however, in the lower Columbia River valley (southwestern Washington and adjacent Oregon). This variant has been called R . macounii var. oreganus .