556 Rosaceae Rubus 



growth of the fioricane be shown graphically on the label. In making an 

 herbarium specimen of Rubus the following should be collected : the primo- 

 cane, and of the fioricane, at least a fifteen-inch section of the base and 

 an equal length of the tip. It is desirable to collect a section of the longest 

 lateral branch of the fioricane if it is well developed. A note on the direc- 

 tion of growth of the floricanes and their range in height should be made. 

 Some authors believe that the species of Rubus freely hybridize and 

 Brainerd, who first named my Rubus, named several of my specimens 

 hybrids and I reported them as such. Bailey, whose determinations I have 

 followed, has referred these specimens to species. These hybrids and their 

 disposal are given in the list of excluded species. 



Plants wholly unarmed (without bristles or prickles). 



Leaves simple, 3-5-lobed; petals purple 1. R. odoratus. 



Leaves 3- (-5) foliolate; petals white 2. R. pubescens. 



Plants more or less armed with bristles or prickles or both. 



Leaves whitish beneath; ripe fruit easily separating from the receptacle as a whole. 

 (Raspberries.) 

 Floricanes arching, dark purple; primocanes and branches of the floricanes 

 glaucous, armed with prickles but lacking long, bristlelike glandular hairs; 

 leaves 3-foliolate or rarely pedately 5-foliolate; inflorescence corymbiform. 



Fruit black 3. R. occidentalis. 



Fruit amber color 3a. J?, occidentalis f. pallidas. 



Floricanes erect (sometimes old ones recurving), dark purple or reddish; primo- 

 canes and branches usually glaucous, armed with prickles and with or with- 

 out long, bristlelike glandular hairs; fruit red at maturity; inflorescence a 

 short raceme. 

 Calyx lobes long-attenuate at the apex, more than 1 cm long; under surface of 



leaflets more or less sparsely covered with long red glandular hairs 



4. R. phoenicolasins. 



Calyx lobes acuminate at the apex, less than 1 cm long; under surface of leaflets 

 without red glandular hairs. 

 Primocanes and floricanes with prickles but lacking long, bristlelike glandular 

 hairs; inflorescence without stipitate glands. (See excluded species no. 



354, p. 1061.) R. idaeus. 



Primocanes and floricanes with both prickles and long, bristlelike glandular 

 hairs; inflorescence with stipitate glands. 

 Surface of the canes, beneath the prickles and glandular hairs, more or less 



densely pubescent 5. R. idaeus var. canadensis. 



Surface of the canes, beneath the prickles and glandular hairs, not pube- 

 scent 5a. R. idaeus var. strigosus. 



Leaves green beneath; ripe fruit not separating from the receptacle. 



Floricanes trailing and rooting more or less at the tips; flowering branches arising 



more or less vertically; flowers mostly with ascending pedicels; primocanes at 



first erect, becoming prostrate. (Dewberries.) 



Canes, branches, and petioles usually more or less densely retrorsely hispid with 



stiff, brown hairs, sometimes the branches and petioles glabrous or nearly 



so (prickles lacking). 



Petals and stamens 5 6. R. hispidus. 



Petals and stamens 10 6a. R. hispidus f. pleniflorus. 



Canes, branches, and petioles more or less prickly, rarely with a few bristles. 

 Pedicels glandless. 



Plants normally stout, with stiff, woody, long-trailing primocanes which are 

 usually not conspicuously scaly-bracted at base; leaves commonly firm 

 and coriaceous when growing in the open 7. R. flagellaris. 



