170 Rydberg: Notes on Rosaceae 



to the ashy gray bark and the petioluled leaflets, characters 

 which I think are not distinctive. In the typical R. gymnocarpa 

 the bark is often light in color on old stems, and many specimens 

 from the range of the typical R. gymnocarpa have more or less 

 petioluled leaflets, such as Jones 1088 and R. S. Williams 876 from 

 Montana, Sheldon 8521 from Oregon, and Allen 72 from Washing- 

 ton. I therefore regard this as a synonym of R. gymnocarpa. 



Rosa abietorum Greene, I take as an unusually bristly R. 

 gymnocarpa. I have been unable to find any constant character. 



Rosa amplifolia Greene. I have not been able to distinguish 

 this from R. gymnocarpa. Dr. Greene's remarks, "the leaves 

 are so very large and have so much the color, texture and pattern 

 of R. acicularis, that but for the small solitary flowers this would 

 have passed readily with many for that species," are at least con- 

 fusing. R. acicularis has rather thick, elliptic leaflets, decidedly 

 pubescent beneath. Dr. Greene must have had an erroneous 

 idea of R. acicularis. 



35. Rosa leucopsis Greene 



This is so close to R. gymnocarpa that I hesitated to admit it 

 as a species. In R. gymnocarpa and R. prionota the leaflets are 

 very thin and reticulate with semi-pellucid veins. In R. leucopsis 

 the leaves are not so thin and the veins are faint and not at all 

 pellucid. Otherwise the three plants are very similar. The 

 species was described from fruiting material; the plant becomes 

 paler in age. 



Rosa Helleri Greene is evidently the same plant in flowers and 

 shows only slight variation from the type of R. leucopsis. The 

 Idaho specimens are mostly like those of the type of R. Helleri, 

 but two numbers of Sandberg, MacDougal & Heller are almost 

 identical with the type of R. leucopsis. 



36. Rosa prionota Greene 



This has been discussed before (see Bull. Torrey Club 44: 

 32. 1917). 



Rosa piscatoria Greene I regard as an unusually strong and 

 bristly plant of R. prionota. 



Rosa apiculata Greene was so named on account of the form 



