2. Topography: The Penstemon angustifolius occurs on 

 moderate to slight (usually less than 10, but occasionally to 

 30 percent grade) upper and middle slopes of hills and ridges 

 on mesa tops and within valley systems. Aspects are typically 

 SW, S, to SE, but occasionally N or NE. Elevations range from 

 1039-1207 m (3410 to 3960 ft) , but within any one population 

 the range is often less than 10 m (31 ft) . 



3. Soil relationships: The plants typically occur on open 

 slopes or within open or deflated areas within denser 

 vegetation, such as blowouts, or cattle trails, sometimes 2- 

 tracks. Many of the soils are sandy loams on hillsides, with 

 gravelly or loamy sands on some ridges. 



E. Population biology and biological interactions 



1. Population size and condition: Populations range from 14 

 to about 60 individuals, with most consisting of 35 to 40 

 plants. Most occupy an area of an acre or less, and most of 

 the plants are concentrated within small locales within the 

 overall area, with a few individuals scattered between, e.g. 

 along cattle trails or 2-tracks. Most of the populations 

 appear healthy, with new shoots or rosettes, indicating 

 recruitment. Some populations contain dead stems from the 

 previous year, and a portion of one appears decadent, with old 

 stems and sterile shoots. 



2. Reproduction: Reproduction is primarily or exclusively by 

 outcrossing. 



3. Competition: The open nature of the habitat indicates 

 little competitive ability. Within denser vegetation, P. 

 angustifolius is concentrated within open areas, such as 

 "blowouts", and scattered elsewhere in less intense conditions 

 such as along cattle trails, 2-tracks, and in deflated areas. 

 Open areas are probably necessary for seedling establishment. 

 It appears that this species has been favored overall by 

 reduction in canopy cover caused by crown fires in the 1988 

 Brewer Fire; though local segments of the population may have 

 been killed under hot temperatures. 



4. Herb ivory: The plants are probably unpalatable, and grow 

 within areas receiving only slight grazing impact. Browsing 

 by wildlife is limited. 



F. Assessment and management recommendations: This species is 

 recurrent across a variety of District settings, and is under no 

 immediate threats. It is recommended that it be dropped from 

 further consideration by the U.S. Forest Service. It will remain 

 on the Montana species of special concern list pending further 

 study. 



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