Rydberg: Notes on Rosaceae 489 



rivale L. and G. urbanum L., has been known for a long time. 

 Geum rivale L. hybridizes also here in America and the following 

 hybrids have been known. As the flowers of G. rivale are quite 

 different from those of most species of the genus, its hybrids are 

 easily distinguished. 



Geum rivale X strictum, G. auranthacum Fries, was the first 

 one to be recognized. It was described from garden material, 

 but the following native specimens are to be referred here: 



Alberta: Macoun 20016. 



New York: Catskills, near Hunter, 1898, Britton; shores of 

 Lake Champlain, 1900, N. L. & E. G. Britton. 



Geum macro pliyll um X rivale, G. pulchrum Fern., is represented 

 by the following specimens: 



Vermont: Mendon, Eggleston. 



Quebec: Bic, 1905, Williams, Collins & Fernald. 



The hybrids between the species of the G. strictum group are 

 not so easily distinguished, partly because the species themselves 

 are closely related and seemingly grade into one another. As the 

 intergrading forms are found in the region where the ranges of 

 two species overlap, they may represent hybrids. As examples 

 of such hybrids may be given the following specimens : 



Geum oregonense ,X strictum. 



Utah: Logan, 1910, George Zundel 206 (in part). 



Montana: Helena, 1908, Butler 798. 



Colorado: Honnold, 1901, Tweedy 4172. 



Geum macro phyllum X oregonense. 



British Columbia: Scagit Valley, 1905, /. M. Macoun 60914. 

 Wyoming: Crevasse Mountain, Yellowstone Park, 1902, 

 M earns 2 191. 



Montana: Tobacco Mountains, 1909, Butler 4231. 

 Oregon: Oregon City, 1905, Lyon 60. 



Geum macro phyllum X strictum. 



Montana: Lake McDonald, 1901, MacDougal 959. 



SIEVERSIA 



This genus was based on Sieversia anemonoides and hence 

 monotypic. In 1823 Robert Brown extended the genus to include 

 all the Geums without articulate styles. This limitation was 



