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..
Caltha flabellifolia Pursh, Fl. Am. Sept. 390. 1814.
Caltha palustris var. flabellifolia T. & G. Fl. N. A. I: 27. 1838.
Weak, slender, reclining or ascending, 1o-1 1/2o long, glabrous. Basal leaves 2'-4' broad, long-petioled, flabelliform or reniform, with a wide open sinus; the upper sessile or short-petioled, similar or with truncate bases, all crenate or dentate; flowers yellow, 6"-9" wide, solitary or 2-3 together; sepals oval; achenes 4-10, about 4" long, com* pressed.
In cold shaded mountain springs, Pocono plateau of Pennsylvania and northern New Jersey to Maryland and recorded from New York. Strikingly different from the preceding in habit and appearance. June-July.
Caltha natans Pall. Reise Russ. 3: 284. 1776.
Stems slender, floating or creeping in wet places, rooting at the nodes, 6'-18' long, branching. Lower and basal leaves slender-petioled, cordate-reniform, 1'-2' wide, crenate or entire, thin, cordate with a narrow sinus; upper leaves short-petioled, smaller; flowers white or pink, 5"-9" broad; sepals oval, ob-tusish; follicles several or numerous, rather densely capitate, about 2" long, the beak short and straight.
3. TRÓLLIUS L. Sp. Pl. 556. 1753.
Erect or ascending perennial herbs, with palmately divided or lobed leaves, thickened fibrous roots, and large usually solitary yellowish, white, or purplish flowers. Sepals 5-15, petaloid, deciduous. Petals 5-15, small, unguiculate, linear, with a nectariferous pit at the base of the blade. Carpels 5-∞, sessile, many-ovuled, forming a head of follicles in fruit. Stamens numerous. [Old German, trol, something round.]
About 12 species, mainly inhabiting marshy places, natives of the north temperate zone. Besides the following, another occurs in western North America. Type species: Trollius europaeus L.
172, name only. 1791. Trollius laxus Salisb. Trans. Linn. Soc. 8: 303. 1803.
Stems slender, weak, ascending, 1°-2° long. Leaves all but the upper petioled (the lower petioles sometimes a foot long), palmately 5-7-parted, 2'-4' wide, the segments obovate, cuneate, lobed, cleft or toothed; flowers generally solitary, 1 1/2' broad; sepals 5-7, ovate or obovate, obtuse, yellowish-green, spreading; petals 15-25, minute, much shorter than the numerous stamens; filaments filiform; anthers linear, 1" long; head of fruit nearly an inch broad, the follicles 4" long, each tipped with a straight subulate beak of one-fourth its length.
T. albiflorus (A. Gray) Rydb., of the Rocky Mountain region, differs in having white sepals.