Ranunculus abortivus L.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Stems erect, branched above, 2–5 dm, glabrous or sometimes puberulent above; basal lvs reniform to rotund, ± cordate at the base, chiefly merely crenate, but one or more of them often variously lobed or divided; cauline lvs sessile or subsessile, usually deeply 3–5-divided, the segments varying from broadly linear and entire to oblanceolate or even obovate and irregularly toothed or incised; pet 2–3 mm, rhombic, shorter than the sep; achenes in a short-ovoid head on a villous receptacle, broadly obovate, turgid, 1.5 mm, the beak very short; 2n=16. Moist or dry woods, abundant and variable; Lab. to Alas., s. to Fla., Tex., and Colo. Apr.–June. The var. eucyclus Fernald, with slender, flexuous stems and suborbicular, deeply cordate basal lvs with narrow sinus, occurs chiefly from N.Y. and N. Engl. to Nf. and Que. Var. abortivus, stouter and more erect, not markedly flexuous, with more reniform basal lvs with a broad sinus, is mostly but not entirely more southern than var. eucyclus. Other described vars. are of doubtful significance.