502 Rydberg : Notes on Rosaceae 



eties of P. nivea. P. Hookeriana, at least, is very distinct, and 

 were it not for the 3-foliolate leaves, I would associate it with the 

 Multifidae group, especially with P. pseudosericea and P. pauci- 

 juga. The style is just as fusiform as in those species and the 

 inflorescence is compact as in that group, not open as in the typical 

 species of the Niveae. 



Dr. Wolf also regards P. prostrata as a variety of P. nivea, in 

 this respect following Dr. Lehmann, but neither Lehmann nor 

 Wolf seems to have seen the type of P. prostrata Rottboell. Dr. 

 Wolf refers to it a specimen collected by Morten Pedersen, labeled 

 as P. quinqaefolia Rydb., but according to Wolf, better referable to 

 P. nivea macro phytta. It is probably Pedersen 4Q6 that is referred 

 to, but this has nothing to do with P. prostrata Rottb. The type 

 of the latter is in the herbarium of the Botanical Garden at 

 Copenhagen, where I saw it in 1901 and drew from it the descrip- 

 tion which is found in the North American Flora. I have seen 

 no other specimen resembling it, and no form of P. nivea or of any 

 of the species often included in it approaches it. The leaflets 

 resemble those of P. gracilis but are three in number, and the 

 flower and inflorescence are different. 



New York Botanical Garden". 



