Rydberg: Notes on Rosace ae 503 



leaves, scarcely 5 mm. long, is referred doubtfully to this species. 

 It is Vernon Bailey 2019 of the Death Valley expedition. 



Cercocarpus arizonicus Jones. This species is much more local 

 than C. intricatus. It is closely related to it, perhaps not distinct 

 If C. hypoleucus were found in the region this might be a hybrid 

 between that species and C. intricatus. 



Utah: Deep Creek, 1891, M. E. Jones; Tropic, 1894, Jones. 



Nevada: Rock Mountains, 1898, Purpus 6336?. 



Hybrids 



Mr. Coville has collected specimens which are without doubt 

 a hybrid between C. ledifolius and C. macrurus. A specimen of 

 the hybrid and one of each of the two parents is mounted on the 

 same sheet, his no. 1523 in the National Herbarium. When these 

 two species hybridize, it would be expected that some of the more 

 closely related species might do so. This may explain some of 

 the intermediate forms between C. betuloides and C. Douglasii, 

 between C. montanus and C.flabellifolius, and between C. ledifolius 

 and C. intricatus. 



Also a specimen collected by M. E. Jones at Silver Reef in 

 1894 seems to be a hybrid of C. ledifolius and C. arizonicus. A 

 specimen of the latter is included under the same number, 5149k, 

 and C. ledifolius is found in the region. 



New York Botanical Garden 



