120 ROSACEAE 



Leaflets dissected into linear or oblong divisions. 8. P. brunnescens. 



Leaflets coarsely toothed with lanceolate teeth. 9. P. Nuttallii. 



Caly.x and leaves not gland iilar-atomiferous ; plant neither yellowish nor brownish; ribs 

 of the leaves not prominent. 

 Pubescence of the stem and petioles appressed. 

 Leaflets coarsely toothe-d. 



Leaflets obovate or oblanceolate, toothed to near the base. 



10. P. jucunda. 

 Leaflets cuneate-obovate, the middle ones mostly toothed above the middle, 

 entire at the base. 31. P. glaucophylla. 



Leaflets dissected at least half-way to the midrib. 



Leaves rather densely sill^y beneath. 11. P. rectiformis. 



Leaves glabrous e.xcept the veins. 12. P. glabrata. 



Pubescence of the stem and petioles spreading; leaflets loosely hairy, often slightly 

 tomentose beneath. 13. P. dascia. 



III. Candidae. 



Segments of the leaflets lanceolate, acute; tomentum sparse. 22. P. viridescens. 



Segments of the leaflets oblong to linear, obtusish; tomentum dense. 

 Pubescence of the petioles and stems appressed. 



Leaves densely yellowish silky above, snow-white, tomentose and silky beneath. 



14. P. Candida. 

 Leaves green and sparingly silky above, tomentose, but neither snow-white nor 

 silky beneath. 15. P. Pecten. 



Pubescence of the petioles and stem spreading. 16. P. Bakeri. 



IV. Pectinisectae. 



Leaves green, finely silky beneath, slightly if at all tomentose. 17. P. pectinisecta. 

 Leaves white-tomentose beneath. 



Divisions of tlie leaflets scarcely revolute; petals 7-10 mm., long. 



Leaves loosely villous-tomentose above. 18. P. lonqiloha. 



Leav'es appressed-silky above. 19. P. Blaschkeana. 



Divisions of the leaflets narrowly linear, revolute; petals 5-7 mm. long. 



20. P. flabelliformis. 



V. Graciles. 



Leaflets cut-toothed or cleft with lanceolate teeth. 



Leaflets with a cuneate entire base; tomentum sparse. 21. P. intermittens. 



Leaflets toothed or cleft along cheir whole margins. 

 Petioles with appressed or ascending hairs. 



Stem slender, 3-5 dm. high; inflorescence open, scarcely leafy. 



22. P. viridescens. 

 Stem stout, 4—7 dm. high, erect, leafy as well as the inflorescence. 



Leaves grajish green beneath, only slightly tomentose. 



23. P. glomerata. 

 Leaves densely white-tomentose beneath; stem densely hairy. 



24. P. dichroa. 

 Petioles with spreading hairs. 



Leaflets of at least the stem-leaves oblanceolate, sparingly hairy or glabrate 



above; petals often 1 cm. long. 25. P. gracilis. 



Leaflets obovate, densely hairy above; plant 3—4 dm. high; petals 5-6 mm. 

 long. 26. P. camporum. 



Leaflets merely crenate with rounded or ovate teeth. 27. P. fiUpes. 



VI. SUBJUG.'VE. 



One species. 28. P. subjuga. 



VII. Aureae. 



Leaflets toothed, the toothing not deeper than half-way to the midrib. 

 Leaflets crenate with rounded or rounded-ovate, obtuse teeth. 



29. P. Vreelandii. 

 Leaflets closely toothed or cleft with lanceolate or oblong, acute or barely obtusish 

 teeth or segments. 

 Leaflets spatulate or obovate; teeth usually spreading. 35. P. concinnacformis. 

 Leaflets cuneate or cuneate-oblanceolate, toothed above the middle, teeth ascend- 

 ing. 

 Leaves rather densely silky-strigose, the basal ones often inclined to be pin- 

 nate. 30. P. dirersifoUa. 

 Leaves slightly pubescent, in age glabrous and somewhat glaucous, digitate. 



31. P. glaucophylla. 

 Leaflets cleft or divided, the divisions extending two-thirds to the midrib or further. 



Leaflets cleft into oblong or lanceolate divisions, shghtly sUky-strigose, in age glabrate. 



32. P. perdissccla. 

 Leaflets divided into linear divisions, permanently strigose. 33. P. multisecta. 



VIII. Coxcinxae. 



Leaflets densely silvery-sUky on both sides, only sliglitly if at all tomentose beneath. 

 Leaflets deeply dissected. 15. P. Pecten. 



Leaflets merely toothed. 



Inflorescence many-flowered and dense. 34. P. fastigiata. 



Inflorescence few-flowered and open. 35. P. concinnaeformis. 



