30 

 HABITAT 



1. ASSOCIATED VEGETATION: Species found in 

 association with H. rarif lorum (at one or more 

 sites) included: 



Clarkia pulchella (ragged robin) 

 Madia exiqua (little tarweed) 

 Madia minima (small head tarweed) 

 Mimulus f loribundus (purple-stem monkey- 

 flower) 



Myosotis micrantha (blue scorpion-grass) 

 Selaqinella wallacei (Wallace selaginella) 



2. TOPOGRAPHY: This species occurs on steep slopes 

 in the Bull River valley. 



3. SOIL RELATIONSHIPS: Heterocodon rarif lorum was 

 found in areas with less dense vegetation, and it 

 is possible that it requires bare soil for 

 seedling establishment. 



4. REGIONAL CLIMATE: The mountains of northwestern 

 Montana are dominated by a cool temperate climate. 

 The weather collection site at Trout Creek Ranger 

 Station is approximately 15 miles east of the Bull 

 River valley, and at an elevation of 2,370 feet. 

 The H. rariflorum sites are at 4,000 to 4,700 feet 

 in elevation. For the period from 1951-1980, the 

 July mean temperature at Trout Creek Ranger 

 Station was 65.0° F, the January mean was 24.1° F, 

 and the mean annual precipitation was 30,49 inches 

 (U.S. Department of Commerce 1982). 



POPULATION DEMOGRAPHY AND BIOLOGY 



1. PHENOLOGY: Heterocodon rariflorum flowers and 

 fruits from June through August (Hitchcock et al. 

 1955-1969) . In the Bull River valley of Montana, 

 this species had finished flowering by the end of 

 June, and may have begun to flower in late May. 



2. POPULATION SIZE AND CONDITION: This species 

 occurs in small colonies in the Bull River valley. 

 Observed populations were in good condition, 

 although some weedy species were present. 



3. REPRODUCTIVE BIOLOGY 



a. TYPE OF REPRODUCTION: This annual species 

 reproduces by seed. 



