Saxifragaceae. 83 



180; Shirasawa, 249; Ward, 1:198, f. 100. R. nigrum. Bose- 

 mann, 48; Fant, 19, f. 14; Schneider, f. 181; Ward, 1:206, f. 

 107; Willkomm, 31, f. 40. R. petraeum. Schneider, f. 182; 

 Willkomm, 9, 31, f. 39. "R.rotundifolium" [oxycanthoidcs.'\. 

 Brendel, pi. 3. R. rubrum. Bosemann, 48; Fant, 19; Schnei- 

 der, f. 181. R. sanguineum. Bosemann, 48; Schneider, f. 182. 



1. Evergreen: stems prickly. R. speciosum. 

 Deciduous. 2. 



2. Buds ovoid, glandular or puberulent: leaf-scars rather 

 broad. 3. 



Buds elongated subfusiform: leaf-scars very narrow. 7. 



3. Bud-scales and twigs with some sessile resin-glands, gla- 

 brate. 4. 



Without sessile resin-glands: buds gray-puberulent. 5. 



4. Resin-glands minute: wood fetid. R. nigrum. 

 Glands large and conspicuous. R. americanum. 



5. Twigs quickly glabrate. 6. 

 Twigs rather persistently gray-puberulent. R. odoratum. 



6. Spreading and stoloniferous. R. triste. 

 Bushy: commonly planted. (Red currant). 



(1). R. vulgare. 



7. With very frequent prickles. 8. 

 Unarmed. 14. 



8. Infra-axillary prickles often large (2X10 mm. or more): 

 buds glossy straw-colored. (2). R. missouriense. 



Prickles smaller: buds dull brown. 9. 



9. Buds short (3 mm.), downy. R. rotundifolium. 

 Buds rather long (5 cr 6 mm.). 10. 



10. Infra-axillary prickles scarcely larger than the abundant 

 others: twigs and buds glossy straw-colored. 



R. lacustre. 



11. Infra-axillary prickles longer, if accompanied by others. 11. 

 Twigs quickly nearly white, with exfoliating epidermis. 12. 

 Epidermis more persistent. 13. 



