16 



The Bannack site has a mountain mahogany/bluebunch 

 wheatgrass ( Elymus spicatus ) habitat type with limber pine 

 occurring as a subdominant species. Associated forbs at 

 this site include Allium textile , Artemisia f rigida , 

 Cryptantha celosioides , Delphinium bicolor ssp. novum, 

 Petrophyton caespitosum , Townsendia spathulata , and two 

 other Montana species of special concern, Lesguerella sp. 

 novum I and Sphaeromeria argentea . 



2. Topography: In Montana, tapertip biscuitroot occurs on 

 mountain and canyon slopes ranging in elevation from 6,200 

 to 8,500 feet. Near Bannack it grows on the west facing 

 slopes and top of the limestone ridge to the east of 

 Hangman's Gulch between 6,200 and 6,400 feet. 



3. Soil relationships: In Montana, Lomatium attenuatum grows 

 in talus and gravelly to rocky soils derived from limestone. 

 Evert (1983) describes the soils where the species is found 

 in Wyoming as "lithosols derived from volcanic material or 

 limestone." It has not yet been found on volcanics in 

 Montana. The soil at the Bannack site is a shallow, loose, 

 gravelly clay derived from Madison limestone, but Lomatium 

 attenuatum usually grows in microsites with substrates 

 better classified as gravel or scree, often next to bedrock 

 outcrops. 



D. POPULATION DEMOGRAPHY AND BIOLOGY 



1. Demographic details: The population at Bannack was 

 estimated to consist of between 1,000 and 10,000 plants and 

 to cover approximately 40 acres. About 50% of the plants 

 were reproductive and 50% were vegetative. 



2. Reproductive biology: Reproduction is by seed. The flowers 

 appear with the leaves in spring (Evert 1983). At Bannack, 

 most reproductive plants were in a mature fruiting stage 

 with just a few still flowering on the survey date (June 

 12). Specimens which I collected have between 2 and 30 

 mature fruits per plant and there is a range in maturity 

 between umbellets on a plant. 



