124 ROSACEAE. 



Though they often present marked and characteristic dif- 

 ferences when really comparable parts are compared, the 

 roses differ so greatly in their individual branches that any 

 effort to key the species out on vegetative characters must be 

 taken with a large degree of allowance for fallibility. 



1. Prostrate: evergreen. (Memorial rose). R. Wichuraiana. 

 Scrambling or climbing, or fountain-like. 2. 



Bushy: deciduous. 4. 



2. Evergreen: very prickly. (Macartney rose). R. bracteata. 

 Deciduous. 3. 



3. Forming fountain-like clumps. 



(Prairie rose). R. setigera. 

 High climbing. (Ramblers). R. multiflora. 



4. Small (scarcely a half-meter high as a rule). 5. 

 Taller (usually 1-2 m. high). 6. 



5. Prickles widened at base. 



(Baby rambler). R. multiflora var. 

 Prickles needle-like. (Wild roses). 



R. acicularis, humilis, pratincola and Woodsii. 



6. Essentially unarmed except the suckers. R. blanda. 

 Characteristically prickly. 7. 



7. Prickles needle-like, nearly straight. 8. 

 Prickles flattened at base or strongly hooked. 10. 



8. Stems stout: planted everywhere. R. rugosa. 

 Stems rather slender. 9. 



9. Rather dwarf. (Scotch rose). R. spinosissima. 

 About 2 m. high. (Yellow rose). R. foetida. 



10. Stems green. 11. 

 Stems red or purple. 12. 



11. Prickles much dilated. (Dog rose). R. canina. 

 Prickles not greatly dilated. 



(Sweetbrier). R. rubiginosa. 



12. Stems rather pink and glaucous. R. rubrifolia. 

 Stems purple. R. cinnamomea. 



