This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Ranunculus bulbosus L. Sp. Pl. 554. 1753.
Erect from a bulbous-thickened base, hairy, 6-18' high. Leaves petioled, 3-divided, the terminal division stalked, the lateral ones sessile or nearly so, all variously lobed and cleft, flowers bright yellow, about 1' broad; petals 5-7, much longer than the reflexed sepals, obovate, rounded; head of fruit globose, 5"-6" broad; achenes compressed, very short-beaked.
In fields and along roadsides, New England to North Carolina, Tennessee and Louisiana. Naturalized from Europe. May-June. In England the name Buttercups is chiefly applied to this species and to R. repens and R. acris; called also in middle English Kingcups, Goldcups, Butter-flowers and Blister-flowers. Frogwort. Pilewort. Golden knops. Cuckoo-buds. Pissabed. Horse-gold. St. Anthony's-turnip. May-July.
Ranunculus pennsylvanicus L. f. Suppl. 272 1781.
Erect, branching, pilose-hispid, 1°-2° high, leafy. Leaves thin, 3-divided; divisions stalked, deeply 3-cleft, the lobes lanceolate, cuneate, acute, incised; flowers yellow, 3"-4" wide; petals equalling the reflexed sepals or shorter; head of fruit oblong or cylindric, 3" thick, sometimes 6" long; achenes smooth, pointed with a sharp beak one-third their length; receptacle conic, hairy.
In wet, open places, Nova Scotia to Georgia, British Columbia, Kansas and Colorado. June-Aug.
Ranunculus hispidus Hook. Fl. Bor. Am. 1:19. 1829.
12: 3. 1892.
Erect or diffuse, hairy, branching, 1°-2° high. Leaves 3-divided, the blade 2-3' long, the divisions broadly * oblong to ovate, acute, cuneate, variously cleft and lobed; flowers 5"-6" broad, yellow, the petals exceeding the spreading or slightly reflexed calyx; head of fruit globose to oblong, 4" thick; achenes smooth, pointed with a sharp beak about one-fourth their length; receptacle obovoid.
Ranunculus repens L. Sp. Pl. 554. 1753.
R, Clintoni Beck, Bot. N. & Mid. States 9. 1833.
Generally hairy, sometimes only slightly so, spreading by runners and forming large patches. Leaves petioled, 3-divided, the terminal division, or all three stalked, all ovate, cuneate or truncate, acute, cleft and lobed, often blotched; flowers nearly 1' broad; petals obovate, much exceeding the spreading sepals; head of fruit globose, 4" in diameter; achenes margined, tipped with a stout short slightly bent beak.
Fields, roadsides, and in wet grounds, Newfoundland to Virginia, Ontario and British Columbia. Bermuda; Jamaica. Mainly introduced from Europe, but regarded as indigenous in its western range. Ram's-claws. Gold-knops. Butter-daisy. Horse-gold. Sitfast. Yellow gowan. Spotted-leaf buttercup. May-July.