15 



Saussurea densa (G3S1) 



In addition, it grows in the same habitat as 

 Antennaria aromatica , currently considered a 

 Category 2 species (USDI 1990) though it is 

 widespread in Montana. 



7. Population biology of the taxon. 



A. General summary: Populations of Erigeron 

 lackschewitzii range in numbers from 5-500 

 individual plants, with the median being ca. 100. 

 Populations at or above median size are usually 

 concentrated in small areas of less than ten acres, 

 while diffuse populations may be spread for over a 

 mile. 



B. Demography. 



1. Known populations: Twelve (Note: two pairs of 

 sites tallied as separate populations lie 

 within 1 mile of one another; Corrugate Ridge 

 and Mount Patric Gass, and Our Lake and 

 Headquarters Creek Pass) 



2. General demographic details (Montana): 



a. site (001) Mount Wright 



1. Area occupied by population: 2 



2. Estimated number of individuals: ca. 



100 



b. site (002) Headwaters Creek Pass 



1. Area occupied by population: 10 



2. Estimated number of individuals: 



200-300 



c. site (003) Sock Lake 



1. Area occupied by population: 2 



2. Estimated number of individuals: 500 



d. site (004) Corrugate Ridge 



1. Area occupied by population: 10 



2. Estimated nvimber of individuals: 



fewer than 2 00 



e. site (005) Mount Patrick Gass 



1. Area occupied by population: 2 



2. Estimated number of individuals: 



110-140 



