8 R. pusillus Poir. Erect; lvs. all petiolate, lower ones ovate, upper ones linear-lanceolate; pet. mostly but 3 scarcely longer than the calyx; stam. 8 - 10; carpels ovate, scarcely pointed. - In wet grounds, N. Y. to Ga. and La. Stems slender, weak, 6 - 12' high, dichotomously branched. Lower lvs. subcordate, 1/2 - 1' long. 1/3 as wide, petioles 1 - 3" long, upper ones 1 - 1 1/2" long, 1/4 as wide, with minute, remote teeth. Fls. very small, yellow, on long peduncles. May.
9 R. oblongifolius Ell. Erect or ascending, diffuse, branched; lvs. lance-ovate and lanceolate; fls. minute, stam. about 20. - Car., Ga., and W. Glabrous, or stem puberulent, 12 - 18' high, dividing above in numerous slender branches and peduncles. Lvs. petiolate, denticulate, upper linear. Fls. numerous, petals yellow, less than 1" long. Carp, minute, pointless, in round heads. (R. Texensis Engl.)
10 R. abortivus L. Smooth; radical lvs. roundish, cordate, crenate, petiolate; cal. a little longer than petals, reflexed. A very pretty species in woods, Can. to Ark., remarkable for the dissimilarity of the root and stem leaves. Stem 8 - 16' high, nearly naked. Root lvs. 8 - 18" diam., quite regularly margined with crenate divisions, and on petioles 2 - 5' long. Lower stem lvs. pedate, with a pentangular outline; upper in 3 deep, linear segments, sessile. Fls. small, yellow. Fruit in globous heads. May, Jn.
β micranthus. Hairy, low (3 - 5'); lower lvs. scarcely cordate, 3-lobed or 3-cleft. Fls. 1 or 2. Mass. (Sprague) to Ga. 1 (R. micranthus, Nutt.)
11 R. rhomboideus Goldie. Hirsutely pubescent, much branched; root lvs. rhomboid-ovate, crenate-dentate, on long petioles; sep. spreading, shorter than the petals; ach. smooth, with very short beaks. - Wis. (Lapham) and Can. W. A low, bushy, hairy species, 6 - 10' high. Root lvs. about 1' by 2/3', often roundish or elliptical, the petioles about 2' long. Segments of the stem leaves linear-oblong, obtuse, oftener entire. Petals yellow, oblong-obovate. Heads of carpels globous. (R. ovalis and brevicaulis, Hook.)
12 R. fascicularis Muhl. Early Crowfoot. Erect; root fasciculate; radical lvs. appearing pinnate; peduncles terete; carpels scarcely margined. - Rocky woods and hills. Root a cluster of fleshy fibres. Root lvs. on petioles 3 - 8' long, ter-nate, with the middle segment long-stalked and again pinnately ternate; lateral segm. mostly sessile, all 3 - 5 cleft into acute lobes. Stems never creeping. Pubescence silky, appressed. Fls. bright yellow, 1' broad. Petals spatulato-obovate, with a broad scale. Beak of the carpels slender. Apr., May.
13 R. repens L. Boot fibrous; radical lvs. ternate with stalked leaflets; peduncles furrowed; carp, broadly margined and pointed. - In moist and shady places. Early flowering stems erect; later branches from the base prostrate, 1 - 3 - 4f long, generally hirsute at the base. Petioles hairy, long. Lvs. hairy on the veins, dark green, ternate, the lfts. ovato or broadly crenate, variously lobed and cleft, all (or at least the middle ones) potiolulate. Fls. middle size, bright yellow. Fr. in a round head. May, - Jl. Varies exceedingly in different localities and stages of growth. Some of its more striking forms are:
β. linearilobus. St. very long, floriferous, smoothish; lobes of lvs. very narrow. Fruit not strongly margined.
y. hispidus. Stem and petioles densely hirsute with soft-spreading hairs; lfts. all distinctly stalked, deeply parted. Fr. short-pointed.
6. nitidus. Mostly erect, glabrous; fls. large, sep. reflexed; fr. strongly margined. Common South. Probably a distinct species.
14 R. palmatus E1l. Lvs. palmately 3 - 5 cleft or divided, with the sinus at base closed, the segm. all sessile and cut-toothed or lobed; carp. few, margined, and straight-beaked. - In wet barrens, Car. to Fla. St. 12 - 18' high, with a few slender branches, pubescent. Lvs. all petiolate, pentangular in outline, 1 - 2' wide, with appressed pubescence. Upper lvs. of 3 linear segments. Fls. few, yellow, small (6 - 8" diam.) Fr. compressed.
15 R. acris L. Butter-cups. St. erect, many-flowered; lvs. more or less pubescent, deeply trifid, with the base segm. divaricate, all laciniatc, upper ones with linear segments; ped. terete; cal. hairy, spreading; carp. roundish, smooth, compressed; beak short, recurved. - This is the most common species in N. Eng. and Can., in meadows and pastures, rapidly and extensively spreading. St. 1 - 2f high, round, hollow, mostly hairy. Lvs. 1 1/2 - 3' diam., upper ones in 3 linear segments. Fls. large (1' diam.), golden yellow. Jn., Sept.
β. plena. Fls. double, the petals excessively multiplied. Gardens.
16 R. Pennsylvanicus L. Hirsute, with stiff, spreading hairs lvs. ternate, lfts. sub-petiolate, deeply 3-lobed, incisely serrate; cal. reflexed, rather longer than the roundish petals; carp. tipped with a short, straight style. - A very hairy species in wet grounds, Can. and U. S. Stem l 1/4 - 3f high. Lvs. 2 - 3' diam., lfts. strongly veined and with spreading segments. Fls. numerous, small, bright yellow. Fruit in dense oblong or cylindrical heads. - Jn., Aug. (R. hispidus Ph.)
17 R. sceleratua Ph. Smooth; lower lvs. 3-parted, segm. 3-lobed, crenately incised, or entire; carp. minute, pointless. - Grows in wet places, Can. to Ga. St. rather thick, hollow, much branched, 1 - 1 1/2 f high. Lower petioles 3 - 5' long, with rather large, palmately 3 - 5-parted leaves. Floral lvs. or bracts mostly simple, lanceolate and entire. Fls. small, yellow. Cal. reflexed, as long as the minute petals. Hds. of carpels only 2 - 3" long. This is one of the most acrid of the tribe, and will raise blisters upon the skin. Jn., Jl.
18 R. recurvatus L. Hirsute with thin, spreading hairs; lvs. all similarly 3-parted, segm. oval, unequally incised, the lateral ones 2-lobed; cal. recurved, longer than the lanceolate petals; ach. with a hooked beak. - About 1 f high, in damp woods. Lab. to Fla. Palo green, branching above. Lvs. 1 1/2 - 2' long, 2 - 3 1/4' wide, on petioles 3 - 6' long. Upper lvs. subsessile and 3-parted quite to the base. Fls. small, with inconspicuous, pale yellow petals. Carp. ovate, tipped with long, hooked beaks. May - Jl.