4. Herbivory: Wind, water, and gravity are downslope 

 dispersal vectors. Long-term retention of the Eriogonum 

 visheri population mosaic pattern across the landscape may be 

 linked to animal dispersal vectors, including passerine birds 

 and least chipmunks, as suggested by Ode (1987). 



F. Assessment and management recommendations: Dakota buckwheat 

 is a sensitive species on Custer National Forest now known from the 

 Sioux District. Water developments for livestock are discouraged in 

 the vicinity. Consultation with the Custer National Forest - Cedar 

 District and the South Dakota Natural Heritage Program is necessary 

 to determine how this site fits into monitoring and protection 

 plans. 



The Slim Buttes population shifted downslope under heavy rains and 

 Badlands slope erosion in 1993. A relatively high proportion are 

 in sandy outwash flats where they are subject to occasional 

 livestock trampling and competition with more mesic species. 

 Grazing has limited direct impact, but heavy grazing favors exotic 

 plants which may compete with Eriogonum visheri . 



A. Description 



Festuca idahoenis Elmer 



Poaceae 



Idaho fescue 



1. General description: Herbaceous perennial bunchgrass, 3 0- 

 100 cm (11.8-39.3 in) tall; with inrolled leaf blades, short 

 ligules less than 2 mm (.08 in), awned lemmas with awns 

 shorter than the length of the body, elongate blades over half 

 the length of the culm; panicle somewhat open, and usually 

 over 10 cm (4 in) long (from Hitchcock 1971) . 



2. Technical description: Culms usually densely tufted in 

 large bunches, 30-100 cm tall,; blades numerous, usually 

 elongate, very scabrous, rarely smooth, filiform, involute; 

 panicle narrow, 10-20 cm long, the branches ascending or 

 appressed, somewhat spreading in anthesis; spikelets mostly 5- 

 to 7-f lowered; lemmas nearly terete, about 7 mm long; awn 

 usually 2 to 4 mm long. 



3. Diagnostic characteristics: Festuca idahoensis differs 

 from F. ovina in panicle length, plant height, and leaf blade 

 length. Festuca idahoenis is relatively larger in all 

 respects, with panicle length 10-20 cm (4-7.9 in) vs. mostly 

 less than 10 cm; plant height 30-100 cm (11.8-39.3 in) tall 

 vs. mostly less than 3 cm tall; and leaf blades elongate and 

 over half as long as the culms, vs. blades mostly less than 

 half as long as the culms. It also has lemmas about 7 mm (.3 

 in) long, vs. 4-5 mm (.16-. 2 in) long (from Hitchcock 1971). 



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