440 ROSACEAE 



Hypantbium decidedly pear-shaped or elliptic, acute at the base, ^ith a dis- 

 tinct neck at the top. » 



Sepals rarely more than 1 cm. long; barkyellowish green. 5. R, collaris. 

 Sepals 2-3 cm. long; bark brown. 



Leaflets conspicuously glandular-granuliferous, but scarcely at all hairv 

 beneath, rounded-oval, double-toothed. 6. R. Engelmannii. 



Leaflets densely pubesccTit, but rarelj slightly if at all gland iilar-gran- 

 uUferous beneath, mostly elhptic, simple-toothed. 

 _. 7, R. acicularis. 



Hj-panthium subglobose, almost without a neck, 8. R, Bourgeauiana. 



Infrastipular prickles usually present. 



Flowers mostly solitary; petals usually 2.5 cm. long or more; fruit 12-20 ram thick. 

 Prickles straight or nearly so. 



Hypantluiim densely prickly. 9. B. MacDougali. 



Hypanthium not prickly or rarely slightly so. 



Leaflets more or less double-toothed, more or less glandular-granulifer- 

 ous beneath; stipules and rachis glandular. 

 Leaflets very thhi. pale and slightly glandular-granuliferous, but 



not muriculate beneath. 10. R. nutkana. 



Leaflets thicker, dark green on both sides, conspicuously glandular- 

 muriculate beneath. 11. R, muriculata. 



Leaflets simple-toothed, puberulent but not glandular-granuliferous 

 beneath; rachis rarely glandular. 12. R. Spaldingii, 



Prickles more or less distinctly curved. 

 Hypanthium prickly. 



Stem stout. 1 m. high or more; leaflets usually more than 3 cm. long. 



c^ , „ , 13. R. Underu-oodii, 



Stem low, usually less than 3 dm. high; leaflets usually not more than 

 2 cm. long. 16, r^ aciculata. 



Hypanthium smooth. 



Prickles very large and flat; twigs densely glandular and pubescent. 



T» ' 1 7 X, ^ J , 14. .B. Vurandii, 



iTickles short and slender, not conspicuously flattened; twigs not con- 

 spicuously glandular, mostly glabrous. 



Leaflets perfectly glabrous or merely glandular-granxiliferous be- 

 neath. 



r 



Stem 1 m. high or more; leaflets usually more than 2 cm. long. 

 ^1 ®^^? ^^^^ green, rather firm, rarely double-serrate, not 

 glandular-granuliferous beneath; calyx not densely glandular. 



c- « , , 15. R. melina. 



btem usuafly less than 3 dm. high; leaflets usually less than 2 

 cm. long, dark green, glandular-double-toothed; calyx usually 

 T^ n covered ^ath stalked glands. 16. R. aciculata. 



•pi-.«-^,.e r^^ ^Leaflets sparingly pubescent beneath. 17. R. oreophila. 



FloM ers mostly corymbose, if solitary the petals 2 cm. long or less; fruit rarely 



more than 1 cm. thick. 

 Prickles more or less curved. 



Leaflets finely puberulent or glandular-granuUferous, or both beneath, 

 nypantmum ellipsoid; yoimg shoots with rather few strong curved 



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Hj-panthium globose; young shoots with flne. often rather many prick- 



T>ri}f^l^f^^ perfectly glabrous. 20. R. manca. 



Prickles straight or nearly so. 



Hypanthium globose; neck usually obsolete. 



Stipules, petioles, and rachis conspicuously glandular. 



Q^j 1 .. , _, 21. R. Fendleri. 



fetipuies. petioles, and rachis not conspicuously glandular, usually 



Leaflets glabrous or nearly so. 



Leaves yellowish green; fruit orange; corymb several-flowered. 

 T ^ , . 22. R. chrysocarpa. 



Leaves aark green above, paler beneath; fruit purpUsh red; 



Leaflets more or less pubescent beneath. 



Leaflets elliptic or oval, equally green on both sides. 



Leaflets broadly oval, thin, 2-5 cm. long; plant nearly un- 



T^.^^^^" , 24. R. saliciorum. 



Leaflets narrowly oval, less than 3 cm. long, rather Arm; 



T^..fl..*^^^^^*^^^^^''-, ». 25. R. uUramontana. 



Leaflets oboyate, or if elhptic. more or less glaucous beneath. 



i^eatlets thm. very sharj^ly serrate, equally green on both 

 siaes; sepals with a few slender bristles near the margins; 



ToJ^V^^i^^ ^'^^*' s|^»^er- 26. R. praetincta, 



stouter^^^' ^ beneath; sepals without bristles; prickles 



Hypanthium elongai'c^ear-shaped. with a distinct n^L^' ^^^"^"""• 

 Pistils few; styles deciduous with the upper part of the hypantMui^? whicf falL' off as a 



