ROSACBAE (ROSE FAMILY) 483 



AirsMie. - Roadsides and waste plaoeS: local, Mass. to N. J. and Mich. (Adv, 

 from Eu.) 



■H- ++ Flowers in rather compact scarcely leafy chymes {stems only l-2-flowered 



in a. 11). 



= Leaves 5-^-foliolate ; flowers numerous. 



9. P. Nuttdllii Lehm. Stems several, ascending from a stoutish ba,3e, 2-? 

 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. — 

 Meadows and banks of streams, Minn., Man., and westw. June-Aug. 



10. P. KECTA L. Stems upright, very leafy, 8-7 dm. high, loosely hirsute ; 

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

 on both surfaces, paler beneath ; calyx hirsute ; 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 3-foliolate ; flowers 1 or 2. 



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

 broadly cuneate-obovate, deeply 3-5-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. 



■1- -1- Leaves pinnate. 



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

 the upper surfaces of the leaves a little darker; stems ascending, 1.5-J6 dm. 

 high, slender, branching above into a diffuse cyme; leaflets b-W, 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. Mex. 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, cuneale- 

 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 ^ongy. 



14. P. paliistris (L.) Scop. (Maksh 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. 

 (Oomarum 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. fruticdsa L. (Shrubby C.) Stem erect, shrubby, 1-8 dm. high, 

 much branched ; leaves pinnate ; ZecyJcis 5-7, crowded, oblong-lanceolate, cretiVe, 

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

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

 Great L. region, n. la., Ariz., and Cal. June-Sept. (Eurasia.) 



16. P. tridentkta Ait. (THREE-TOOTHisr) 0.) Stems low (3-22 cm. high), 

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

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

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

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

 tions, N. J., and southw. on the upper AUeghenies ; also westw. chiefly along 

 tlie Great Lakes. June-Aug. 



