ROSACEAE. 181 



Leaves mainly digitate, rarely pinnate with approximate leaflets or with a pair 



of small leaflets on the petioles. 

 Leaves or at least the basal ones s-Q-foliolate. 



Additional smaller leaflets on the petioles not present. 

 Plants less than 2 dm. high. 



Leaves tomentose at least beneath. II. CONCINNAE. 



Leaves not tomentose. III. AUREAE. 



Plants more than 2. dm. high. IV. GRACILES. 



Additional smaller leaflets on the petioles present. V. SUBJUGAE. 



Leaves 3-foliolate, tomentose beneath. VI. NIVEAE. 



Leaves manifestly pinnate. 



Style not longer than the mature achenes, thickened or glandular below ; leaves 

 more or less tomentose, but not necessarily white beneath. 



VII. MULTIFIDAE. 



Style much longer than the mature achenes, filiform. 

 Leaflets approximate, 3-7. 



Leaves tomentose beneath. VIII. RUBRICAULES. 



Leaves not at all tomentose. III. AUREAE. 



Leaflets rather distant 7-21. 



Leaves green on both sides and only slightly hairy. 



IX. MULTIJUGAE. 

 Leaves grayish or whitish, silky or tomentose. X. LEUCOPHYLLAE. 



I. SUPINAE. 



Achenes with a corky gibbosity on the upper suture ; leaves pinnate with 3-5 

 pairs of leaflets. i. p. paradoxa. 



Achenes not gibbous. 



Leaves pinnate, with 2 approximate pairs of leaflets ; the upper ternate. 



2. P. rivalis. 

 Leaves all ternate (or the lower rarely digitately s-foliate). 



Petals shorter than the sepals ; achenes whitish. 



Stem diffusely branched, spreading ; leaflets cuneate ; inflorescence cymose. 



3. P. leucocarpa. 

 Stem erect, strict ; leaflets broadly obovate ; inflorescence falsely racemose. 



4. P. lateriflora. 

 Petals about equalling the sepals ; stem stout, strict ; achenes brownish. 



5. P. monspeliensis. 



II. CONCINNAE. 

 Middle leaflet sessile. 



Leaflets obovate or cuneate, deeply toothed or incised. 6. P. concinna. 



Leaflets oblong, with entire margins, only 3-toothed (rarely 5-toothed) at the 



very apex. 7 . p. bicrenata. 



Middle leaflet petioled. 8. P. quinquefolia. 



III. AUREAE. 

 Only one species. 9 . p. dissecta. 



IV. GRACILES. 



Leaves green on both sides, not at all tomentose beneath. 



Leaflets cuneate at the base, usually toothed only above the middle ; plants low, 



usually less than 3 dm. high. 9. p. dissecta. 



Leaflets oblanceolate, toothed to near the base; plants 3-6 dm. high. 



Stem glabrous or appressed-pubescent ; leaflets coarsely toothed or cleft half- 

 way to the mid-rib or less. 

 Slender; leaves thin, not strongly ribbed; inflorescence open; bracts small. 



10. P. jucunda. 



Stout; leaves thick and strongly ribbed; inflorescence dense; bracts con- 

 spicuous, u. p. Nuttallii. 



