160 ROSACE.^, (rose family.) 



•*- -(- Leaves palmate, of 3 or 5 leaflets ; tomentose or villous. 



8. P. argentea, L. (Silvery Cinque-foil.) Stems ascending, pauicu- 

 lately branclied at the summit, many-flowered, white-woolly ; leaflets 5, wedge- 

 oblong, almost pinnatifid, entire toward the base, with revolute margins, green 

 above, white with silvery wool beneath. — Dry barren fields, etc., N. Scotia to 

 N. J., west to Dak. and E. Kan. June -Sept. (Eu.) 



9. P. frigida, Till. Dwarf (1-3' high), tufted, villous when young; 

 leaflets 3, broadly cuneate-obovate, deeply 3-5-toothed at summit, nearly gla- 

 brous above ; flowers mostly solitary, small, on very slender stems ; bractlets 

 and sepals equal. — Alpine summits of the White Mts. (Eu.) 



* * Style lateral; purple petals {shorter than the broad calyx) somewhat persist- 



ent; disk thick and hairy; achenes glabrous; hairy receptacle becoming 

 large and spongy. 



10. P. paliistris, Scop. (Marsh Five-Fixger.) Stems stout, ascend- 

 ing from a decumbent rooting perennial base (^ - 2° long), glabrous below ; 

 leaves pinnate; leaflets 5-7, oblong, serrate, lighter colored and more or less 

 pubescent beneath ; flowers few in an open cyme ; calyx {V broad) dark purple 

 inside. — Cool bogs, N. J. to N. Ind., 111., Minn., and northward. (Eu.) 



* * * Style attached below the middle ; achenes and receptacle densely villous ; 



icoody pe7-ennials. 



11. P. fruticosa, L. (Shrubby Cinque-foil.) Stem erect, shrubby 

 (1-4° high), much branched; leaves pinnate; leaflets 5-7, crowded, oblong- 

 lanceolate, entire, silky, usually whiter beneath and the margins revolute ; 

 petals yellow, orbicidar. — Wet grounds. Lab. to N. J., west to Minn., northern 

 Iowa, and north and westward. June -Sept. (Eu.) 



12. P. tridentata, Ait. (Three-toothed C.) Stems low (1-10' high), 

 rather woody at base, tufted, ascending, cymosely several-flowered; leaves 

 palmate ; leaflets 3, wedge-oblong, nearly smooth, thick, coarsely 3-toothed at 

 the apex ; petals ivhite ; achenes and receptacle very hairy. — Coast of N. Eng. 

 from Cape Cod northward, Norfolk, Ct. {Barbour), and mountain-tops of the 

 Alleghauies ; also shores of the upper Great Lakes, and N. Iowa, Wise, and 

 Minn. 



§ 3. Styles flliform, lateral ; peduncles axillary, solitary, l-flowered ; achenes 

 glabrous; receptacle very villous; herbaceous perennials, with yellow flowers. 



13. P. Anserina, L. (Silver-AVeed.) Spreading by slender many- 

 jointed runners, ichite-tomentose and silk y-v ill ou s ; leaves all radical, pinnate; 

 leaflets 7-21, with smaller ones interposed, oblong, sharply serrate, silky to- 

 mentose at least beneath ; bractlets and stipules often incisely cleft ; pedun- 

 cles elongated. — Brackish marshes, river-banks, etc., New Eng. to N. J., N. 

 Ind., Minn., and northward. (Eu.) 



14. P. Canadensis, L. (Comjion Cinque-foil or Five-Finger.) Stems 

 slender and decumbent or prostrate, or sometimes erect ; pubescence villous, often 

 scanty ; leaves ternate, but apparently quinate by the parting of the lateral leaf- 

 lets ; leaflets cuneate-oblong or -obovate, incisely serrate, nearly glabrous above ; 

 bractlets entire. — Dry soil ; common and variable. Apr. - July. — Often pro- 

 ducing summer runners. 



