Notes on Rosaceae — I 



Per Axel Rydberg 



The author has thought it advisable to publish a series of 

 notes on this family, supplementary to his monograph in the 

 North American Flora, vol. 22, beginning on page 239. The 

 reasons for so doing, are : 



I. The plan of the North American Flora does not alio 



w 



many critical notes and explanations, and many facts worthy of 



presentation must necessarily be omitted on account of lack of 

 space. 



2 - It is not always evident from the synonymy alone, why a 

 ce rtain name should be adopted in preference to another. 



3- It is often desirable to present the author's reasons for his 

 ■imitation of genera and species. 



4- In the North American Flora, only the types of new species 

 given. It is often desirable to cite some more specimens, 



would help in identification of these species, when the types 



which 



are not accessible. 



Opulaster Medic. 



Th 



ere may be some doubt as to whether this genus was 



Properly published. The original publication consists only of 

 " t,n g Spiraea opulifolia L. as a synonym of Opulaster bullatus 

 ' ed |c. Icotorus Raf., Epicostorus Raf., and Physocarpa Raf, were 

 Polished in about the same way. The only name for the genus, 

 1 lc h was accompanied by an adequate description, was Physo- 

 c *V*s Maxim. ; but this, as well as Physocarpa Raf., is invalidated 

 ythe older Physocarpon Necker,* and Physocarpum Bercht. & 

 resl »t which both have Latin diagnoses. Under the latter, there 

 are also two species named and described. There is, therefore, 

 no a lternative left but the retaining of Opulaster as the name of the 



b 



s » unless the making of a new name. is preferred. 



* 1? 



Jlem. Bot. a : 164. I79* 

 T Kost l- 1 : Ranunc. 14. 1823. 



535 



