ledifolius) , big sagebrush {Artemisia tridentata) , and a 

 gooseberry (Ribes setosum) . Subdominant grasses in these 

 habitats include bluebunch wheatgrass {Elymus spicatus) 

 and western grass {Leucopoa kingii) . Forbs which are 

 often more closely associated with Agastache cusickii 

 than the above listed dominants include the talus adapted 

 perennials Arenaria nuttallii, Oenothera caespitosa, 

 Phacelia hastata, and Penstemon montanus , and annuals 

 such as Collinsia parviflora and Polygonum douglasii. 

 Photographic slides showing the vegetation at each of the 

 three sites on the Beaverhead National Forest are 

 attached at the end of this report. 



Topography: On the Beaverhead National Forest, Agastache 

 cusickii is confined to the southerly facing slopes of 

 narrow canyons, at elevations ranging from 7,000 to 7,600 

 feet. The BLM site is similar but is on a slope facing a 

 broader valley and has a slightly lower minimum 

 elevation. The population centers are on steep, loose 

 talus downslope from limestone outcrops, often in chutes, 

 but a few plants are usually found on more level talus 

 deposits at the base of the slopes. Photographic slides 

 of the population sites are attached at the end of this 

 report. 



Soil relationships: Soil development is minimal on the 

 limestone talus where Agastache cusickii grows in the 

 Tendoys, however, at the BLM site where the banks have 

 been cut by quarrying, some horizonation can be seen; 

 fine particles have been weathered and leached from the 

 surface layer and deposited at depths. The upper zone of 

 the talus is thus extremely well drained but the clays 

 confer a higher water holding capacity in the lower zone. 

 Agastache cusickii seems to be confined to the smaller 

 sizes of limestone talus found in the area. The 

 substrate is constantly settling and shifting and is 

 easily disturbed. 



E. POPULATION DEMOGRAPHY AND BIOLOGY 



1. Demographic details: Populations of Agastache cusickii 

 on the Beaverhead National Forest are rather small and 

 local, with estimates of numbers and area ranging from 

 100 plants (considered as clumps of aerial stems) 

 covering a single acre at Kelmbeck Creek (004) to 1,000 

 plants covering 15 acres in Patterson Canyon (003). The 

 Williamson-Wood Canyon (002) population is intermediate 

 with an estimated 200-500 plants over 5 acres. The BLM ' s 

 Big Sheep Creek population is larger and more extensive 

 in comparison. 



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