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..
Potentilla millegrana Engelm.; Lehm. Ind. Sem. Hamb. 1849: Add. 12. 1849.
Potentilla leucocarpa Rydb. in Britt. & Brown, 1ll. Fl. 2: 212. 1897.
Decumbent or ascending, annual, usually weak and diffusely branched, 6'-3° high, softly villous-pubescent, or glabrate. Stipules ovate or ovate-lanceolate, entire or sparingly dentate; leaves all but the uppermost petioled, 3-foliolate; leaflets oblong, cuneate, thin, flaccid, more or less pubescent, incisely serrate, 1/2'-1 1/2' long; flowers several, terminal, loosely cymose, yellow, about 2" broad; calyx-lobes ovate, acute, about equalling the lanceolate bractlets, exceeding the obovate petals; stamens about 10; style slightly thickened below, terminal; achenes small, glabrous.
Potentilla rivālis Nutt., a western species which may reach our limits in western Nebraska, is distinguished from this by its usually pinnately 5-foliolate leaves, viscid pubescence, stricter erect habit, and more numerous stamens. It has been collected at the stockyards of Chicago.
8. Potentilla monspeliénsis L. Rough Cinque-foil. Barren Strawberry. Fie. 2234.
Potentilla monspeliensis L. Sp. Pl. 499. 1753. Potentilla norvegica L. Sp. Pl. 499. 1753. Potentilla hirsuta Michx. Fl. Bor. Am. 1: 302. 1803. P. labradorica Lehm. Del. Sem. Hort. Hamb. 1849: 12. 1849.
Erect, stout, annual or biennial, branched above, hirsutely rough-pubescent, 6'-2 1/2o high. Stipules foliaceous, incised-dentate or sometimes entire; leaves 3-foliolate, the lower and basal ones petioled, the upper sessile or nearly so; leaflets obovate, green both sides, obtuse at the apex, mostly narrowed at the base, pubescent with spreading hairs, 1'-2' long; flowers yellow, terminal, usually rather densely cymose and leafy-bracted, 3"-6" broad; calyx-lobes ovate, acute, pubescent, a little longer than the obovate retuse petals and somewhat broader than the bractlets; stamens 15-20; style glandular-thickened below; achenes glabrous, rugose or smooth.
In dry soil, Newfoundland and Labrador to South Carolina, Tennessee, Alaska, Kansas, Arizona and California. Also in Mexico, Europe and Asia. Often occurs as a weed in cultivated ground; consists of several races. June-Sept.
P. pentandra Engelm.; T. & G. Fl. N. A. 1: 447. 1840. Potentilla rivalis var. pentandra S. Wats. Proc. Am. Acad. 8: 553. 1873.
Similar to the preceding species, erect, hirsute, 1°-4° high, simple at the base, much branched above. Stipules lanceolate, somewhat foliaceous, dentate or entire; basal and lower leaves slender-petioled, 3-foliolate, with the lower pair of leaflets parted nearly to the base, so as to appear 4- or 5-foliolate; leaflets oblanceolate or oblong, obtuse at the apex, narrowed or cuneate at the base, incised-dentate, glabrous or sparingly pubescent above, quite pubescent beneath, 1'-2' long; flowers terminal, in a more or less flat-topped cyme, pale yellow, 2"-4" broad; calyx-lobes ovate, acute, exceeding the small spatu-late petals, and equalling or slightly shorter than the lanceolate bractlets; stamens 5-8; style thickened below; achenes glabrous.
In sandy soil, Manitoba to Alberta, Missouri, Nebraska and Arkansas. June-Sept.