B. UPDATE OF GEOGRAPHICAL DISTRIBUTION (MONTANA) 



No additional populations of Penstenon lemhiensis were 

 newly discovered in Montana in 1991. Thus, the total 

 number of known element occurrences in the state 

 remains at 44. Of these, 42 have been recently 

 documented (1983-1990), one recent report (1987, 

 Medicine Lodge Cree)c) has not been relocated, and one 

 is an unverified historical record (1947) (Montana 

 Natural Heritage Program database, Helena) . 



C. POPULATION DEMOGRAPHY AND MONITORING STUDIES 



1. DEMOGRAPHIC STUDIES 



The three permanent monitoring transects 

 established in 1989 were re-read on 29-30 July 

 1991, using the methods described in a previous 

 report (Shelly 1990) . The population and 

 fecundity data are summarized in Table 1. The 

 numbers of plants and the numbers of fruiting 

 individuals, for each transect over the three-year 

 study period, are displayed in Figures 1-3, pp. 4- 

 6. 



In 1991, the total number of plants in the three 

 transects was 115. This total represents a severe 

 continuing decline, from 240 plants in 1989 and 

 215 plants in 1990. Once again, further decreases 

 occurred in the French Creek - Park Mine and 

 Badger Pass North transects. Total population 

 size decreased from the 1990 level at the French 

 Creek - Discovery Mine transect, but equalled the 

 original total present in 1989. 



The total number of plants in the French Creek - 

 Park Mine transect decreased by 31 from the 1990 

 total, resulting in a population decline of 52%. 

 Extensive sheet erosion appears to be continuing 

 at the site, and may have been a contributing 

 factor in the loss of the 55 established plants 

 that have not survived from 1989 to 1991. The 

 fecundity and vigor of the surviving individuals 

 in this transect was drastically lower in 1991; no 

 plants flowered or fruited. Additionally, no 

 fruiting plants were found in the vicinity of the 

 transect, so we were unable to collect data on 

 seed production for this site. 



The total number of plants at the French Creek - 

 Discovery Mine transect decreased by 12 in 1991, 

 resulting in a -25.5% population growth rate. 



