Fl. Boston., 137. 1814.
Stems erect or ascending, never rooting nodally, strigose or spreading-strigose, base not bulbous. Roots always both filiform and tuberous on same stem. Basal leaf blades ovate to broadly ovate in outline, 3-5-foliolate, 2.1-4.7 × 1.9-4.5 cm, leaflets undivided or 1×-lobed or -parted, ultimate segments oblanceolate or obovate, margins entire or with few teeth, apex rounded-acute to rounded-obtuse. Flowers: receptacle hispid or glabrous; sepals spreading or sometimes reflexed from base, 5-7 × 2-3 mm, hispid or glabrous; petals 5(-7), yellow, 8-14 × 3-6 mm. Heads of achenes globose or ovoid, 5-9 × 5-8 mm; achenes 2-2.8 × 1.8-2.2 mm, glabrous, margin forming narrow rib 0.1-0.2 mm wide; beak persistent, filiform, straight, 1.2-2.8 mm. 2n = 32.
Phenology: Flowering winter–spring (Jan–Jun).
Habitat: Grassland or deciduous forest
Elevation: 0-300 m
Man., Ont., Ala., Ark., Conn., Ga., Ill., Ind., Iowa, Kans., Ky., La., Md., Mass., Mich., Minn., Miss., Mo., Nebr., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., S.C., Tenn., Tex., Vt., Va., Wis.
Ranunculus fascicularis is very similar to R. hispidus var. hispidus, and herbarium specimens without underground parts may be difficult to identify. Ranunculus fascicularis grows in drier habitats; segments of its leaves are commonly oblanceolate and blunt, with few or no marginal teeth; and its petals are widest at or below the middle. Ranunculus hispidus var. hispidus is usually larger in all its parts (leaves, flowers, heads of achenes); leaf segments are variable in shape but their apices are normally sharper and their marginal teeth more numerous, and petals are widest above the middle.