Stems prostrate or ascending, 4-15 cm, glabrous, each with 1-4 flowers. Roots cylindric, 1-3 mm thick. Basal leaves persistent, blades reniform or obovate to very narrowly elliptic, 0.7-5.2 × 1-2 cm, base truncate, obtuse or attenuate, margins entire or with 3 broad, apical crenae, apex rounded to acute. Flowers: pedicels glabrous or nearly so; receptacle glabrous; sepals 5-8 × 3-7 mm, abaxially glabrous or sparsely pilose, hairs colorless; petals 5-10, 8-13 × 5-12 mm; nectary scale glabrous or ciliate. Heads of achenes globose, 7-12(-20) × 6-11(-20) mm; achenes 1.4-2.2 × 1.1-1.8 mm, usually finely pubescent; beak subulate or lance-subulate, straight or curved, 0.4-1 mm.
Alta., B.C., Sask., Ariz., Calif., Colo., Idaho, Mont., N.Dak., N.Mex., Nebr., Nev., Oreg., S.Dak., Utah, Wash., Wyo.
Varieties 2 (2 in the flora).
Usually only a minority of the ovaries develop, and the fruiting receptacle is completely hidden by aborted ovaries. Populations growing at high elevations (Ranunculus glaberrimus var. ellipticus) and low elevations (var. glaberrimus) are usually well differentiated, but these varieties intergrade at intermediate elevations.
The Thompson Indians rubbed the flowers or the whole plant of Ranunculus glaberrimus on arrow points as a poison (D. E. Moerman 1986).
|1||Basal leaf blades ovate to obovate, usually shallowly lobed; bracts 3-lobed, lobes equal in size; 400–2000 m.||Ranunculus glaberrimus var. glaberrimus|
|1||Basal leaf blades elliptic to oblanceolate, usually undivided; bracts 3-lobed, middle lobe much larger; 1200–3600 m.||Ranunculus glaberrimus var. ellipticus|