41 



British Columbia to northern Oregon along the east 

 side of the Cascade Mountains, and then east into 

 Saskatchewan, Idaho, Montana, Wyoming, and South 

 Dakota (Hess 1969) . In Montana, this species is 

 known from one site each in Lincoln, and Sanders 

 counties, and two sites in Missoula County, in 

 northwestern Montana. The distribution of this 

 taxon in Montana is presented in Figure 7, p. 46. 



2. CURRENT SITES: The Bull River Campground (001) 

 location was first observed in 1986 and again 

 during survey work in 1989; it is the only 

 recently verified location for S. x pyramidata in 

 Montana. The other locations along Pete Creek 

 (002), East Fork Lolo Creek (003), and Lolo Creek 

 (004) were last verified in 1965, 1970, and 1937, 

 respectively. 



3. UNVERIFIED/UNDOCUMENTED REPORTS: None at present. 

 HABITAT 



1. ASSOCIATED VEGETATION: The Spiraea x pyramidata 

 population at Bull River Campground (001) occurs 

 in a powerline corridor adjacent to the 

 campground. A disturbed habitat is typical of 

 this taxon (Hess 1969) . Other species occurring 

 at this site include the disturbance-related 

 Pteridium aquilinum and S. betulifolia , as well as 

 Rubus parvif lorus . Aralia nudicaulis and Rosa 

 woodsii . S. douqlassi occurs nearby along the 

 Bull River and in shaded areas in the campground. 



2. TOPOGRAPHY: Spiraea x py.tramidata populations are 

 most commonly found in valley bottoms (Hitchcock 

 et al. 1955-1969) , in areas with low relief. The 

 microsites where this species occurs are usually 

 somewhat dry and sandy (Hess 1969) . 



The population at Bull River Campground (001) is 

 at 2,300 feet in elevation, and is found in dry 

 soils on a 10 percent slope; it is less than one 

 quarter mile from the Bull River. 



3. SOIL RELATIONSHIPS: Hess (1969) states that S. x 

 pyramidata is "almost always found on disturbed 

 areas such as roadsides, highways, railways, 

 forest camps, and homesites," with either or both 

 suspected parent also present. This indicates 

 that the species appears to require mineral soil 

 for establishment. It is possible that, like 



