86 ROSACEA. (ROSE FAMILY.) 



^_ 4- Style attached below the middle of the ovary : carpels on short pedicels, and^ 

 with the receptacle, densely villous : disk not thickened: more or less woody 

 perennials. 



15. P. fruticosa, L. Shrubby, much branched, 1 to 4 feet high : pubes- 

 cence silky-villous : leaves pinnate; leaflets 5 to 7, crowded, oblong-lanceolate, 

 entire, usually white beneath and the margins revolute. — From Colorado 

 westward to N. California, northward to the Arctic Circle, and eastward to 

 New Jersey and Labrador. 



* # * Styles filiform, attached to the middle of the ovary : peduncles axillary^ 

 solitary, 1-fioivered : carpels glabrous : stems creeping or decumbent : herbaceous 

 perennials. 



16. P. Anserina, L. Spreading by slender many-jointed runners, white- 

 tomentose and silky-villous : leaves all radical, pinnate ; leaflets 7 to 21, with 

 smaller ones interposed, sharply serrate, silky-tomentose at least beneath. — ■ 

 From California, New Mexico, Illinois, and Pennsylvania northward to the 

 Arctic Ocean and Greenland. 



17. SIBBALDIA, L. 



Petals linear-oblong. Styles lateral. — Dwarf and cespitose arctic or al- 

 pine perennials : leaves thick ; the leaflets few-toothed at the truncate summit : 

 flowers cymose. 



L S. procumbens, L, Somewhat villous: stems creeping, leafy at 

 the extremities : leaflets cuneate : peduncles usually shorter than the leaves : 

 akenes on very short hairy stipes. — Mountains of Colorado and California, 

 and the White INIountains, and northward to Alaska and Greenland. 



18. IVESIA, Torr. &Gray. 



Calyx campanulate Akenes fixed by the middle. ~ Herbaceous peren 

 nials : flowers in cymes or open panicles. 



1. I. Gordoni, Torr. & Gray. Viscid-pubescent or often somewhat hir- 

 sute, or glabrate : stems 3 to 10 inches high from a thick resinous caudex : 

 leaflets obovate, with oblong or spatulate segments ; cauline leaves one or 

 two, pinnatifid. — Pac. R. Rep. vi. 72. Wyoming, Utah, Arizona, and west- 

 ward to California. 



19. CHAM^RHODOS, Bunge. 



Calyx campanulate, deeply 5-cleft ; the base lined with a membranous disk, 

 which is very densely bearded at the margin. Stamens opposite the petals, 

 inserted with them into the sinuses of the calyx above the disk. Styles 

 arising near the base of the ovaries. — Small, erect and branching glandular- 

 pubescent herbs : inflorescence dichotomously cymose. 



1. C. erecta, Bunge. Stem slender, two inches to a foot high, panicu- 

 lately branched above : radical leaves rosulate, ternately or biternately many- 

 cleft ; the upper cauline ones 3 to 5-cleft. — Colorado and northward into 

 British America. 



