540 Rydberg : Notes on Rosaceae 



latifolia 



streams with short broad leaves, rounded at the apex and coarsely 



toothed. 



latifolia 



the stems usually die back each year to near the base. This was 

 described as 5. obovata by Rafinesque. Usually it is very unlike 

 the ordinary S. latifolia, but intermediate forms are not infre- 

 quent. This form needs more field study. 



Ameri 



posed. 



sp 



, pyramidata, the author is inciiiieu 

 Helleri. Hybrids are not uncom- 

 . Noble ana was described by J. D. 



Hooker from a plant raised in a California nursery. It is supposed 

 to be a hybrid between 5. Douglasii and S. salicifolia. As one 

 of the supposed parents is a native of North America and the other 

 is occasionally found spontaneously, and as the plant originate 

 in America apparently without the help of man, it might have been 

 included in the North American Flora, but it was excluded there- 

 from, like all other garden plants. The native species of probable 

 hybrid origin and their probable parents are as follows : 



S. roseata 



densifli 



S. subvillosa = S. Douglasii x densiflora. 

 S. tomenhdosa — S. Douglasii x lucida. 

 S. pyramidata = S. Menziesii X lucida. 

 S. sitbcanescens = S. tomentosa x alba. 



Spiraea tomentulosa, and S. subcancscens are known on y^ ^ 

 the type locality. S. subvillosa has been collected also a 



following station : „ f r 



Oregon: Hood River, Cascade Mountains, Aug. I, I 94- 



E. Lloyd. 



S. roseata has been collected at the following locality : 



J 



Mulford. 



Petrophytum and Kelseya 



It is gratifying to the author, that C. K. Schneider, J^neric 

 conservative dendrologist, has independently raised e . ^ 



rank. The genera are related to Spiraea, but are I »* ^ 



and by the_ stnirfu^c^heuj^ 



*Handb. Laubh. i : 484, 485. 1905 



