3 Soil relationships: In Montana, Lomatium attenuatum 

 grows in talus and gravelly to rocky soils derived from 

 limestone. A soil sample was collected from the 

 Beaverhead National Forest site in the Tendoys, but has 

 not yet been analyzed. Evert (1983) describes the soils 

 where the species is found in Wyoming as "lithosols 

 derived from volcanic material or limestone." The 

 species has not yet been found on volcanics in Montana. 



D. POPULATION DEMOGRAPHY AND BIOLOGY 



1. Demographic details: The population of Lomatium 

 attenuatum on the Beaverhead National Forest was 

 estimated to consist of at least 1,000 plants covering at 

 least 5 acres. The area around and upslope from the 

 ecodata plot was surveyed, but potential habitat downhill 

 was not. Population estimates for other Montana 

 occurrences range from 200 to a maximum of 10,000 plants. 

 A population in the Tendoys on BLM land in Limekiln 

 Canyon is quite extensive, stretching for 2-3 miles in 

 the canyon bottom. 



2. Reproductive biology: Reproduction is by seed. The 

 flowers appear with the leaves in spring (Evert 1983). 

 Plants were in a mature fruiting stage on the survey 

 dates (early June to mid-July) for all Montana 

 populations. 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. 



E. MANAGEMENT CONSIDERATIONS 



The population sites of Lomatium attenuatum in the Tendoys are 

 remote, in near pristine condition, and are not impacted by 

 current land uses. However, the species has a very narrow 

 distribution both in Montana and Wyoming; for this reason, 

 designation of Watch status by the Beaverhead National Forest 

 is appropriate. Management requirements for the species are 

 minimal because the slopes where it grows are not generally 

 accessible to cattle and do not produce timber of commercial 

 quality. The species could be impacted in the future by road 

 construction or mining activities. 



29 



