<. 



ROSACEAE (ROSE FAMILY) 483 



hirsute. — Roadsides and waste places, local, Mass. to N. J. and Mich. (Adv. 

 from Eu.) 



•»-<■ ++ Flowers in rather compact scarcely leafy cymes (stems only 1-2-floicered 



in ii. 11). 



== Leaves o~-9-foliolate ; flowers numerous. 



9. P. Nuttallii Lehin. Stems several, ascending from a stoutish ba3e, 2-7 

 dm. high, somewhat villous or glabrate ; leaflets oblanceolate or spatulate, the 

 narrow divergent teeth extending halfway to the midrib, green above, glabrous 

 or glabrate and scarcely paler beneath ; cyme with few upright branches. — 

 Meadow^s and banks of streams, Minn., Man., and westw. June-Aug. 



■ 10. P. RECTA L. Stems upright, very leafy, 3-7 dm. high, loosely hirsute ; 

 leaflets oblanceolate, with narrowly deltoid divergent teeth, more or less hirsute 

 on both surfaces, paler beneath ; calyx hii-sute ; the showy yellow corolla 2 cm. 

 broad. (P. sulphurea Lam.) — Fields and roadsides. Me. to Ont., 111., and 

 D. C. June-Aug. (Nat. from Eu.) 



= = Leaves S-foliolate ; flowers 1 or 2. 



11. P. Robbinsiana Oakes. Dwarf, tufted, villous when young ; leaflets 

 broadly cuneate-obovate, deeply S-jS-toothed at summit, nearly glabrous above ; 

 flowers mostly solitary, small, on very slender stems ; bractlets and sepals sub- 

 equal. (P.frigida Man. ed. 6, not Vill.) — Alpine summits of the White Mts., 

 N. H. June, early July. 



-(- -f- Leaves pinnate. 



12. P. Hippiina Lehm. Densely white-tomentose and silvery-silky throughout, 

 the upper surfaces of the leaves a little darker; stems ascending, 1.5-6 dm. 

 high, slender, branching above into a diffuse cyme ; leaflets 5-11, cuneate- 

 oblong. incisely toothed at least toward the apex, diminishing uniformly down 

 the rhachis ; carpels 10-30. — Prairies and banks of streams, w'. Minn, to Sask. 

 and N. ]\rex. June-Aug. 



13. P. effusa Dougl. Tomentose throughout and with scattered villous 

 pubescence ; stems ascending, 1-3 dm. high, diffusely branched above ; leaves 

 interruptedly pinnate, the leaflets 5-11, the alternate ones smaller, cuneate- 

 oblong, coarsely incised-serrate or dentate ; carpels 10. — Dry plains, w. Minn, 

 to Assina. and N. Mex. 



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

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

 large and spongy. 



14. P. paliistris (L.) Scop. (Marsh F.) Stems stout, ascending from a 

 decumbent rooting perennial base, 1-6 dm. 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 2-2.5 cm. broad, dark purple inside. 

 (Comarum L.) — Cool bogs. Lab. to Alaska, s. to N. J., Pa., Great L. region, n. 

 la., Wyo., and Cal. June-Aug. (Eurasia.) 



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



woody perennials. 



15. P. fruticbsa L. (Shrubby C.) Stem erect, shrubby, 1-8 dm. high, 

 much branched ; leaves pinnate ; leaflets 5-7, crov:ded, oblong-lanceolate, entire, 

 silky, usually whiter beneath and the margins revolute ; petals yellow, orbicular. 

 (Dasiphora Rydb.) — Wet or dry open gTound, Lab. to Alaska, s. to N. J., Pa., 

 Great L. region, n. la., Ariz., and Cal. June-Sept. (I'urasia.) 



16. P. tridentata Ait. (Thkee-toothkd C.) Stems low (3-22 cm. hi,i:h), 

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

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

 the end; petals ichite ; achenes and receptacle very hairy. {Sibbaldiopsis 

 Rydb.) — Lab. to e. N. E., where common in exposed rocky or gravelly situa- 

 tions, N. J., and south w. on the upper Alleghenies ; also westw. chiefly along 

 the Great Lakes. June-Au2r. 



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