3. UNVERIFIED/UNDOCUMENTED REPORTS: None. 



E. HABITAT 



1. ASSOCIATED VEGETATION: Delphinium andersonii is 



found in sagebrush deserts, juniper woodlands, or 

 open forests of desert ranges (Hitchcock and 

 Cronquist 1964) . In Montana it has been 

 associated with Artemisia arbuscula, Agropyron 

 spicatum , Pinus f lexilis , Juniperus osteosperma . 

 Penstemon laricif olius . Allium textile , and 

 Cr yptantha celosioides . At the Helena National 

 Forest, it was found with Artemisia michauxiana , 

 Agropyron spicatum . Cymopterus terebinthinus , and 

 Oenothera caespitosa . 



2. TOPOGRAPHY: In Montana Delphinium andersonii grows 



on gentle to steep slopes. On the Helena National 

 Forest site D. andersonii occurs at a midway point 

 on the southeast-face of a 60-80% slope. 



3. SOIL RELATIONSHIPS: Delphinium andersonii is 



reported from "loose rich soil" in Jefferson 

 County, dry sandy soils in Carbon County, and from 

 loose limestone talus in the Helena National 

 Forest. 



4. REGIONAL CLIMATE: The climate of west-central 



Montana can generally be classified as cool, dry, 

 and continental, with locally greater amounts of 

 precipitation in the mountains. The closest 

 weather station to the site is at Holter Dam which 

 is about 17 miles northwest with an elevation of 

 3487 feet. The Delphinium andersonii site is at 

 an elevation of 5000 feet. For the period of 

 1951-1980, the mean annual precipitation at Holter 

 Dam was 12.02 inches, the mean January temperature 

 was 24.8°F, and the mean July temperature was 

 69.9°F (U.S. Department of Commerce 1982.) 



F. POPULATION DEMOGRAPHY, BIOLOGY AND SPECIATION 



1. PHENOLOGY: Delphinium andersonii flowers from late 



April through mid-July. In the Helena National 

 Forest, the species was collected in flower in 

 late May. 



2. POPULATION SIZE AND CONDITION: The Delphinium 



andersonii population on the Helena National 

 Forest is quite large (estimated at 1000-10,000 

 individuals) . The populations in Carbon County 

 are small (ca. 50 plants) , and the exact size of 



40 



