11 



4. REGIONAL CLIMATE: The climate of southwestern 

 Montana can generally be classified as dry and 

 cool, although higher amounts of precipitation 

 occur in the mountains. For the distributional 

 area of C. lanceolata var. flava in Montana, the 

 nearest climatological stations are located at 

 East Anaconda (1680 m. (5511 ft.)), Divide 

 (1648 m. (5406 ft.)), and West Yellowstone 

 (2031 m. (6662 ft.)). Data for the period 1951- 

 1980 are provided by the U.S. Department of 

 Commerce (1982). At East Anaconda, the mean 

 annual precipitation was 35.15 cm. (13.84 in.); 

 the mean annual temperature was 5.780C (42.40F), 

 the mean January minimum was -9.720C (14.50F), and 

 the mean July maximum was 25.940C (78.70F). At 

 Divide, the mean annual precipitation was 31.47 

 cm. (12.39 in.); the mean annual temperature was 

 4.830C (40.7OF), the mean January minimum was 

 -13.06OC (8.50F), and the mean July maximum was 

 26. 330c (79.40F). These two stations are at 

 considerably lower elevations than the nearby 

 sites; the habitats are thus expected to be cooler 

 and moister than these recorded figures. The West 

 Yellowstone station is at nearly the same 

 elevation as the site near Hebgen Lake, which is 

 approximately 6 air miles to the west-northwest. 

 The mean annual precipitation was 56.74 cm. (22.34 

 in.); the mean annual temperature was I.6I0C 

 (34.90F), the mean January minimum was -17.830C 

 (-O.IOF), and the mean July maximum was 26.330C 

 (79.40F) . 



F. POPULATION DEMOGRAPHY AND BIOLOGY 



1. PHENOLOGY: In Montana, C. lanceolata var. flava 

 typically begins blooming by early May at the 

 lowest-elevation sites; peak flowering occurs in 

 mid- to late May. At higher elevations (i.e., 

 Vipond Park (003)), flowering can persist into 

 mid-June, and a few individuals have been observed 

 in bloom as late as the first week of July. 

 Yearly climatic differences would influence these 

 events, especially in the higher elevations where 

 dramatic weather shifts often take place. 

 Fruiting begins by late May; it is unknown how 

 long the fruits persist, but it is likely that 

 seed dispersal takes place rapidly after fruit 

 maturation. 



2. POPULATION SIZE 7VND CONDITION: All five 

 populations of C. lanceolata var. flava in Montana 

 are very large. The number of plants at each site 

 was estimated in 1988. They range in size from 

 10,000+ to 35,000+ individuals. The populations 



