116 ROSACEAE. 



stopped by the approach of winter so that their canes, as 

 these long-shoots are called, may die back nearly or quite 

 to the base. In this failure to make advance provision for 

 the winter they stand in marked contrast with such genera 

 as Ailanthus and Tilia, where, early in the season, a starve- 

 ling tip of each branch is cut off cleanly by a self-healed scar. 

 The chief types of Rubus, flowering raspberries, high- 

 bush blackberries, dewberries, red raspberries and black-cap 

 raspberries, are easily known at any season of the year, but 

 the individual species and their hybrids are much confused. 



1. Bark shredding: unarmed. 



(Flowering raspberry). (1). R. odoratus. 

 Bark not shredding: trailing or fountain-like. 2. 



2. Trailing. (Dewberries). 3. 

 Forming open or recurving bushes. 4. 



3. Slender and very . soft-wooded. R. hispidus. 

 Stouter: strong and woody. R. procumbens. 



4. Stems characteristically rooting at tip, mostly 



very glaucous. 5. 

 At most exceptionally stoloniferous. 6. 



5. Prickles strongly hooked. (Blackcap). R. occidentalis. 

 Prickles straighter: canes purple. 



(Purple cane). (2). X R. neglectus. 



6. Shoots very glandular-hairy as well as prickly. 



(Wineberry). R. phoenicolasius. 

 Scarcely glandular-hairy. 7. 



7. Nearly unarmed: dwarf. R. idaeus anomalus. 

 Very prickly or else moderately tall. 8. 



8. Unarmed. R. canadensis. 

 Prickly. 9. 



9. Prickles bristle-like, often represented by warts 



in winter. (Red raspberries). 10. 



Prickles stout and persistent. (3). R. allegheniensis. 



10. Shoots red, brown, orange or purple. (4). R. strigosus. 



Shoots straw-colored. European. R. idaeus. 



