11 



Populations of A. shultziorum and A. molybdenus 

 from Wyoming and Colorado, respectively, also 

 incur a similar continental climate. 



POPULATION DEMOGRAPHY AND BIOLOGY 



1. PHENOLOGY: In Montana, A. molybdenus flowers and 

 fruits from late July through August, depending on 

 climatic conditions and slope aspect. In 1989 

 large numbers of stems in nearly all of the 

 Montana populations were vegetative. Flowering 

 and fruiting was restricted to very small portions 

 of the populations during that year; the exception 

 was Our Lake (002). In 1990, flowering and 

 fruiting at Our Lake (002) was again high, 

 although it appeared that plants which had 

 flowered the year before were not in flower this 

 year. 



Also in 1989, fifty percent of the individuals in 

 surveyed populations of A. molybdenus in Colorado 

 were in flower. During that same year, 

 populations of A. shultziorum in Wyoming only had 

 good fruit production in occasional local areas 

 within sites (Marriott 1990) . 



From these observations, it appears that flowering 

 may be dependent on an interaction of the species' 

 internal rhythms, and local temperature and 

 moisture regimes. 



2. POPULATION SIZE AND CONDITION: Populations of A. 

 molybdenus are generally quite large (often 

 greater then 10,000 stemsf. However, due to this 

 species' ability to establish new ramets through 

 rhizome extension, it is difficult to determine 

 the number of genetic individuals in a population. 

 Low flowering and fruiting frequencies probably 

 limit population increases by way of seedling 

 establishment. 



3. REPRODUCTIVE BIOLOGY 



a. TYPE OF REPRODUCTION: This species is a 



perennial. In 1989, Montana populations were 

 observed to consist of approximately 90 to 95 

 percent vegetative ramets. As stated above, 

 flowering and fruiting was restricted to 

 small portions of the populations. 



The establishment of new colonies through 

 rhizome extension appears to be common to all 



