Rydberg: Notes on Rosaceae 487 



Geum oregonense (Scheutz) Rydb. This was originally de- 

 scribed as a variety of G. urbanum to which it is not closely related. 

 Its relationship is with G. macrophyllutn. Usually it is well dis- 

 tinguished from that species by its open inflorescence, smaller 

 stem-leaves and smaller and usually paler petals, but intermediate 

 forms are not lacking. Some of these at least may be regarded 

 as hybrids. Geum oregonense is common throughout the Rocky 

 Mountains, as well as the Sierra Nevada and the Cascades. In 

 the southern Rockies, G. macrophyllum is not found, but it extends 

 east to northern New England, where G. oregonense is not found 

 at all. In California the characters separating the two species 

 seem to be less marked, and considerable questionable material 

 has been seen. 



Geum perincisus Rydb. Many subarctic specimens which 

 might have been referred to G. oregonense have the upper leaves 

 deeply incised and the petals broader and in form approaching 

 those of G. strictum. It is hard to say whether these should be 

 regarded as a variety of G. oregonense or as a distinct species. 

 I adopted the latter view, because all these specimens were far 

 northern ones and some of them found much further east than 

 any of the typical G. oregonense. The following specimens belong 

 here: 



Alaska: Eagle, Yukon Valley, 1902, Arthur Collier 34, 35; 

 Copper River region, 1902, William L. Poto 147. 



Yukon: Fort Selkirk, 1899, Tarleton 120. 



Mackenzie: Fort Simpson, 1861-62, Onion, Kennicolt & Har- 

 disty; Fort Resolution, 1901, Preble & Preble 154. 



Alberta: Cave Avenue, Banff, McCalla 2074. 



Michigan: Turin, 1901, Barlow. 



Geum strictum Ait. is a very variable species. Usually the 

 terminal leaflet is more or less rhombic, as it is commonly described, 

 but not seldom it is rounded or subreniform as it is in G. macro- 

 phyllum or G. oregonense. It usually can be easily distinguished 

 by its large rounded petals and always by its fruit. The lower 

 portion of the style is never glandular and the upper portion has 

 hairs about twice as long as those of the other two species. Geum 

 scopulorum is the common form of G. strictum in the Rockies, a 

 little less robust than in the East. 



