498 Rvdberg : Notes on Rosaceae 



subjuga. My placing it with that species was done simply because 

 both show a tendency to combining digitate and pinnate characters 

 in the leaves. Dr. Simmons in the Flora of Ellesmereland, has 

 rightly criticized me for so doing. The species was based upon 

 Potent ilia nivea pentaphylla Lehm., as represented by some of the 

 specimens cited in Hooker's Flora Boreali-Americana. Unfor- 

 tunately Dr. Lehmann did not propose the name in the work 

 just mentioned, although he gave a description. His publication 

 of the variety did not appear until 1850.* In the meantime, the 

 name had been taken up by Turczaninow,| but whether for the 

 same plant or not I can not tell. As the name pentaphylla was 

 not available I used another name, P. quinquefolia, and it 

 matters little what plant Turczaninow had, as P. quinquefolia 

 applies to the North American plant characterized in my descrip- 

 tion. In 1900 Mr. Morten Pedersen Porsild sent me a collection 

 of Potentillas from Greenland. I undertook to determine them 

 and also published a paper upon them in the Bulletin of the 

 Torrey Botanical Club for March, 1901. Some of the work was 

 hastily done and several corrections to that paper must be made. 

 One of the mistakes made was that I regarded P. nivea subquinata 

 Lange as identical with P. quinquefolia. Following the Madison 

 amendments to the Rochester Code, I substituted the name P. 

 subquinata (Lange) Rydb. for P. quinquefolia. P. nivea, as well 

 as other 3-foliolate species, has occasionally some of the lower 

 leaves 5-foliolate, but P. quinquefolia has them nearly always so. 

 On account of this confusion, I have been severely criticized both 

 by Dr. Simmons and by Dr. Wolf for regarding P. quinquefolia 

 Rydb. as a distinct species. The former made the following re- 

 marks: "there being not the slightest cause to look upon it as a 

 species as Rydberg has done, probably because he has had no 

 opportunity of studying the plant from nature." If Dr. Simmons 

 had taken a little trouble, he could have found that this statement 

 was not exactly true, for in my monograph, I cited a specimen 

 collected by myself in Montana, viz., Rydberg & Bessey 4397, and 

 I had had opportunity to study it in the field. I have since 

 collected it at two other stations, one in Colorado and one in Utah. 



*Delect. Sem. Hort. Hamb. 1850: 12. 1850. 

 fBull. Soc. Nat. Mosc. 14: 607. 1843. 



