ROSACEA. (ROSE family.) 87 



20. AGRIMONIA, Tourn. Agrimony. 



Tall perennial herbs: leaves interruptedly pinnate: flowers in slender spi- 

 cate racemes, with 3-cleft bracts : fruit pendulous. 



1. A. Eupatoria, L. Leaflets 5 to 7, with minute ones intermixed, 

 oblong-obovate, coarsely toothed : petals twice the length of the calyx. — 

 Colorado; common throughout the Eastern States. 



21. POTERIUM, L. Burnet. 



Stamens 2 to 4 or more : filaments often elongated. — Ours is an annual : 

 leaflets deeply piunatifid, petiolulate : flowers small, perfect in ours. 



1. P. annuum, Nutt. Glabrous, slender, 6 to 15 inches high: leaflets 



4 to 6 pairs, ovate to oblong, with linear segments : flowers greenish, the 

 heads ovoid or oblong: fruit shorter than the bracts. — From the Upper 

 Missouri southward into the Indian Territory ; also in California and Wash- 

 ington. 



22. ROSA, Tourn. Rose. 



Calyx without bractlets. Stamens on the thick margin of the silky disk, 

 which nearly closes the mouth of the calyx. Ovaries several, hairy. — 

 Usually prickly : leaves with mostly serrate leaflets : flowers corymbose or 

 solitary, showy. Watson, Proc. Am. Acad. xx. 324. 



* Sepals connivent and persistent after flowering. 

 -t- No infrastipular spines ; acicular prickles often present : fruit globose. 



1. R. blanda, Ait. Stems 1 to 3 feet high, with usually few prickles or 

 none : stipules dilated, naked and entire, or slightly glandular-toothed ; leaflets 



5 or 7 (rarely 9), cuneate at base and shortly petiolulate, simply and coarsely 

 toothed, glabrous above, paler and glabrous or more or less pubescent beneath, 

 not resinous : flowers corymbose or solitary: sepals entire, hispid. — R. frazini- 

 folia, Gmelin. Within our range at its northeastern boundary, and extending 

 from thence to Newfoundland. 



2. R. Sayi, Schwein. Stems 1 or 2 feet high, thickly covered with prickles: 

 stipules dilated, gland ular-ciliate and resinous ; leaflets 3 to 7, usually sessile 

 and obtuse or subcordate at base, more or less doubly toothed, glabrous or slightly 

 pubescent above, resinous beneath: flowers solitary (rarely 2 or 3) : outer sepals 

 with lateral lobes, not hispid. — Abundant in the mountains from Colorado to 

 British America, thence eastward to Lake Superior. 



3. R. Arkansana, Porter. Stems £ to 6 feet high, more or less densely 

 prickly : stipules narrow, more or less glandular-toothed ; leaflets 7 to 11, nearly 

 sessile or of en petiolulate, somewhat cuneate at base, simply and coarsely toothed, 

 glabrous or more or less pubescent beneath, usually not resinous : flowers corym- 

 bose: outer sepals with one or more lateral lobes, usually not hispid. — Fl. Colo- 

 rado, 38. R. blanda t var. setigera, Crepin. Abundant in the mountains from 

 New Mexico and W. Texas to British America, and eastward to the Upper 

 Mississippi. 



