Ranunculus sardous Crantz
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Annual, usually several-stemmed, 1–6 dm, much branched above; principal lvs mostly clustered near the base, 3-parted, the terminal segment stalked, all segments broadly triangular-obovate, deeply lobed and incised; cauline lvs much smaller, with fewer and narrower segments; fls numerous, long-pedicellate; pet 5–8(–10) mm; receptacle hairy in fr; achenes 30–40, broadly obovate to subrotund, the margin smooth and sharply differentiated, the sides papillate; beak 0.2–0.5 mm; 2n=16, 48. Native of Europe, found here and there in our range as a weed. May–July.