166 ROSACEAE 



6. RUBUS ly. 



Receptacle flat : ovary pubescent above : drupelets crowned with a hairy- 

 cushion. I. S. odoratus. 

 Receptacle convex or conic : ovary glabrous : drupelets glabrous. 

 Fruit falling away from the dry receptacle : petals erect. 

 Stems herbaceous, unarmed ; leaflets green beneath. 



2. R. Americanus. 

 Stems shrubby, armed : leaflets white beneath. 

 Stems prickly, glaucous : fruit purple-black, black or dark red. 

 Fruit purple-black or black : stem very glaucous. 3. R. occidentalis. 

 Fruit dark red : stem slightly glaucous. 4. R. neglcctus. 



Stems bristly, not glaucous : fruit light red. 5. R. strigosus. 



Fruit persistent on a fleshy receptacle : petals spreading. 

 Leaflets with pinnatifid blades. 6. R. laciniaius. 



Leaflets with toothed or incised blades. 

 Stems erect, ascending or recurved. 



Leaf-blades white-woolly beneath. 7. R. cunei/olius. 



Leaf-blades not white-woolly beneath. 

 Branches of the inflorescence and the petioles distinctly glandular- 

 pubescent. 

 Fruit broadly oval or nearly spherical, very juicy. 



8. R. nigrobaccus. 

 Fruit narrowly oblong or thimble-shaped, comparatively dry. 



9. R. Allegheniensis. 

 Branches of the inflorescence and petioles villous, strigose or nearly 



glabrous, scarcely glandular. 

 Inflorescence copiously villous. 10. R. frondosus. 



Inflorescence sparingly villous. 

 Plants low, almost herbaceous, weakly prickly. 



II. R. Randii. 

 Plants tall and shrubby. 

 Plants strongly prickly : leaflets pubescent beneath, doubly 



serrate. 12. R. argulus. 



Plants unarmed or with few weak prickles ; leaflets glabrous 

 beneath, singly serrate. 13. R. Canadensis. 



Stems trailing, creeping or decumbent. 

 Stems merely prickly. 

 Inflorescence several- to many-flowered. 14. R. procumbens. 



Inflorescence usually 1-2-flowered. 15. R. Baileyanus. 



Stems bristly and prickly, sometimes merely bristly. 

 Flowering branches and petioles bristly or glabrous : terminal leaf- 

 lets cuneate. 16. R. hispidus. 

 Flowering branches and petioles prickly : terminal leaflets oblong- 

 elliptic. 17. R. nigricans. 



1. Rubus odoratus L. Purpi,e-fi,owbring Raspberry. (Man. p. 

 495 ; I. F./. 7590.) In rocky woods, N. S. to Mich., Ga. and Tenn.— 

 Pennsylvania: Pikb; Monroe; Northampton; Bucks; Chester; 

 Lancaster ; Montgomery ; York ; Columbia ; Tioga; Huntingdon ; 



Al,I,EGHENY. 



2. Rubus AmerioanuB (Pers.) Britton. Dwarf RASPBERRY. (Man. 

 p. 495 ; I. F. / 1S97.) In swamps, Newf. to Man., N. J. and Iowa.— 



