Spreading-hairy annual or perennial, erect, simple or branched, 3-7 dm; basal lvs soon withering, cauline few, petioled; lf-segments 3, the terminal one stalked, all deeply 3-lobed, the lobes toothed or incised; fls few, short-pedicellate; pet obovate, 2-4 mm, shorter than the reflexed sep; anthers 0.7-1 mm; achenes in a cylindric or ovoid-cylindric head mostly 10-15 mm, subrotund, 1.8-2.7 mm, sharply margined; beak flat-subulate, 0.6-1.4 mm, straight or curved; 2n=16. Marshes, ditchbanks, and wet meadows; Nf. to Alas. and e. Asia, s. to N.J., Pa., O., n. Ind., n. Ill., Minn., and Ariz. July, Aug.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
FNA 1997, Martin and Hutchins 1980, Kearney and Peebles 1969
Duration: Perennial Nativity: Native Lifeform: Forb/Herb General: Perennial with erect, hollow stems, never rooting nodally, the roots never tuberous, to 30 cm or more. Leaves: Numerous, ternately compound, basal leaves broadly cordate in outline, 1.5-7 cm long by 3-9 cm wide, the leaflets cleft into laciniate or toothed segments, ultimate segments narrowly elliptic, with toothed margins and an acute apex. Flowers: Solitary with an hirsute receptacle, with reflexed sepals about 1 mm above base, 3-5 mm long by 1.5-2 mm wide, more or less hispid, 5 yellow petals, 2-5 mm long by 1-2.5 mm wide. Fruits: Cylindric to ovoid head of achenes 9-12 mm tall by 5-7 mm broad, the achenes 2-3 mm long by 1.5-2 mm wide, glabrous with the margin forming a narrow rib, the beak persistent, straight. Ecology: Found in moist to damp soils, along streambanks and in moist sites in forests, woodlands or bottomlands from 3,000-8,000 ft (914-2438 m); flowers June-August. Notes: Distinguished by the erect and hollow stems, the ternately compound leaves and the delicate, minute flowers. Ethnobotany: Used as a hunting medicine, and as a red or yellow dye. Etymology: Ranunculus is from Latin rana, little frog, for the moist habit, while pensylvanicus means of or from Pennsylvania. Synonyms: None Editor: SBuckley, 2010