Custer National Forest in the Ekalaka Hills and 



Long Pines, two populations are on BLM land peripheral to the Ekalaka Hills and Long Pines 



National Forest units, and one is on private land directly adjoining BLM land in the Humbolt 



Hills. 



HABITAT: In Carter County, Penstemon angustifolia grows in sandy substrates of sandhills and 

 prairie slopes associated with sandstone-capped buttes and outcrops. It usually grows in 

 microhabitats with sparse vegetation, such as in "blowouts" or other localized erosion features within 

 grassland communities, sometimes with scattered ponderosa pine. Dominant grasses and sedges of 

 the patchy matrix communities include blue grama (Bouteloua gracilis), prairie sandreed 

 (Calamovilfa longifolia), threadleaf sedge (Carexfilifolia), and little bluestem {Schizachyrium 

 scoparium; syn. Andropogon scoparius). Common associated forbs include sagewort {Artemisia 

 campestris), showy sunflower {Helianthus rigidus), hairy goldenaster {Heterotheca villosa), and 

 western spiderwort {Tradescantia occidentalis; Heidel and Dueholm 1995). 



SPECIES BIOLOGY: Population numbers of the seven Carter County populations found in 1994 

 ranged from 14 to about 60 plants, and populations were described as multi-aged and "healthy". 

 Only one live plant and one dead plant were located at the BLM Belltower Butte population in 1 996, 

 and no plants could be found at the site in 1997. The species was common at Medicine Rocks State 

 where population numbers are in the hundreds. 



ASSESSMENT CONSIDERATIONS: Although populations were small and often confined to 

 isolated, ephemeral microfeatures, no immediate threats to populations were identified by 1 994 

 surveys, and the species was recommended dropped from ftirther consideration as a special status 

 plant by the Custer National Forest (Heidel and Dueholm 1995). Location of two additional Carter 

 County occurrences in 1996 and 1997 further demonstrate a broad distribution oi Penstemon 

 angustifolia in sandy habitats scattered across the landscape of northeastern Carter County. The 

 species appears to be favored by small-scale disturbances, is thought to be unpalatable (Heidel and 

 Dueholm 1995), and is apparently compatible with moderate levels of livestock grazing. In spite of 

 this, we recommend retention of BLM Watch status for the species because the total number of 

 plants documented in Montana remains extremely low, and occurrences outside Carter County are 

 based on old collections. 



This is one of several sand-loving species in the county that are often found with other species of 

 special concern where the habitat is extensive and/or in good condition. 



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