338 PROCEEDINGS OF THE AMERICAN ACADEMY 



+- H- Outer sepals laterally lobed. 



9. R. WooDSii. Spines slender, straight or recurved : stipules short : flow- 

 ers corymbose or solitary, on very short pedicels : fruit globose. — Colorado to 

 British America and the Mississippi. 



* * Receptacle densely prickly. Sepals pinnatifid. 



10. R. MiNUTiFOLiA. Very spiny and prickly : stipules short, narrow ; leaf- 

 lets very small: flowers small, solitary, on very short pedicels : fruit globose. 

 — Lower California. 



II. — Sepals spreading after flowering and deciduous. Infrastipular spines pres- 

 ent, often with scattered prickles. 



A. — Styles distinct, numerous, persistent. Base of the calyx persistent on the 

 globose fruit. Caly.\, receptacle, and pedicel hispid. Teeth simple and 

 pubescence not resinous, except in R. Mexicana. 



* Pedicels usually elongated, and leaflets seven. Eastern species. 



■*- Leaflets finely many-toothed. 



11. R. Carolina. Tall, with stout straight or recurved spines : stipules 

 narrow; leaves dull green: flowers corymbose or solitary; outer sepals occa- 

 sionally lobed. — Nova Scotia to Florida and the Mississippi. 



■4- -t- Leaflets coarsely toothed. 



12. R. LnciDA. Often tall, with stout straight or recurved spines : stipules 

 dilated ; leaflets smooth and sliining above : flowers corymbose or solitary ; 

 outer sepals frequently lobed. — Newfoundland to New York. 



13. R. HUMiMs. Low, with straight slender spines: stipules narrow: flow- 

 ers corymbose or solitary; outer sepals always lobed. — From the Atlantic 

 coast to the Mississippi. 



14. R. NiTiDA. Low, with straight slender spines and very prickly : stipules 

 dilated; leaflets glabrous: flowers mostly solitary ; sepals entire. — Newfound- 

 land to New England. 



» * Pedicels very short : leaflets and stipules narrow : flowers solitary ; outer 



sepals lobed. 



15. R. FOLiOLOSA. Spines short, straight or curved : leaflets 7 to 11, glabrous 

 or nearly so. — Indian Territory to Texas. 



IG. 11. Mexicaxa. Spines stout, straight: leaflets 5 to 7, resinous beneath 

 and doubl}' toothed. — Coahuila, Mexico. 



B. — Styles connate into a smooth slender column, persistent. Sepals short ; 



base of the calyx persistent. 



17. R. SETiGERA. Climbing, witii stout recurved spines and no prickles: 

 stipules very narrow ; leaflets 3 or 5 : flowers corymbose : fruit oblong to 

 globose. — Ontario to the Gulf of Mexico. 



C. — Styles few, distinct, the summits with the calyx deciduous from the very 

 contracted top of the smooth receptacle. Sepals sliort. 



18. R. gtmnocarpa. Spines straight, slender: stipules narrow; leaflets 

 doubly serrate: flowers small, solitary or few. — British Columbia to \Vestern 

 Montana and California. 



