Z. IMTRODDCTIOM 



Penstemon lenhiensis (Keck) Keck and Cronquist (Lenhl 

 beardtongue) is a showy perennial in the Figwort Paaily 

 (Scrophulariaceae) . It is a regional endeaic in three counties 

 of southwestern Montana (Beaverhead, Ravalli and silver Bow) and 

 one county of eastern Idaho. It is a Category 2 species 

 candidate for listing as a threatened or endangered species by 

 the U.S. Fish and Wildlife Service (USDI 1990). It is currently 

 ranked as G3/S2 (globally vulnerable, state inperiled) by the 

 Montana Natural Heritage Prograa (Lesica and Shelly 1991) , 

 considered sensitive by Region 1 of the U.S. Forest Service (USDA 

 1988) and considered sensitive in the draft list by the Bureau of 

 Land Management State Office (USDI 1993). 



Penstemon lenhiensis occupies grassland habitat of variable 

 elevation, which is subject to alteration by grazing, mining 

 activity and weed control by herbicide spraying (Schassberger 

 1990, Shelly 1990) . Its populations include a relatively few 

 number of large populations in undisturbed habitat, and 

 relatively many small populations in habitats of manmade 

 disturbance such as roadsides. We suspect that the large 

 populations in natural settings are more stable than the small 

 populations through time, and that the latter are more prone to 

 local extirpation. 



Population counts have been made at large population sites since 

 1986, including the BLM Badger Pass exclosure site, documenting 

 marked increases and decreases in population size (Achuff and 

 Shelly 1991) . There is a need to monitor the populations to 

 differentiate natural fluctuations from overall trend and 

 identify critical life history stages so that an assessment of 

 long term viability can be made. 



The purpose of this project is to study Penstemon lemhiensis life 

 history; monitoring growth, fecundity, recruitment, and mortality 

 to determine overall trend in two populations of Penstemon 

 lehiniensis at two sites representing relatively natural and 

 unnatural settings. This information is needed to interpret data 

 on the location and size of Penstemon lemhiensis populations, it 

 augments monitoring studies in natural settings elsewhere in both 

 states, and it provides a sensitive species management baseline 

 for BLM. 



Penstemon lemhiensis is being monitored on Beaverhead National 

 Forest in Montana, and BLM land in both Montana and Idaho. 

 Populations on the Beaverhead National Forest have been monitored 

 since 1989 (Achuff and Shelly 1991, Shelly 1990, 1993) and are 

 all located within ten miles of the Badger Pass BLM site. In 

 1990, plants within a recently-constructed BLM monitoring 

 exclosure near Badger Pass Microwave Tower were marked and 

 described, encompassing most or all of a population in an intact 



