57 



populations are known in Montana; two 

 recently observed sites are known in Idaho. 

 In Montana, the sites occur within an area 

 of approximately 370 square miles. The 

 total number of individuals from all of the 

 known populations in Montana is roughly 

 estimated to be 13000-15000; the average 

 population size is approximately 290. 



2. General demographic details (Table 3, p. 58). 



C. Phenology. 



1. Patterns: Open flowers were observed from 

 late July through late August; anthesis 

 probably occurs for about 5-6 weeks, starting 

 in mid-July. Many plants had developing 

 fruit by the third week of August, and seed 

 dispersal probably occurs through September. 

 The plants are most conspicuous and easily 

 identifiable in the field in late July and 

 ear 1 y August . 



2. Relation to climate and microclimate: 



Details unknown; may continue flowering 

 later in areas which retain soil moisture 

 later in the summer. 



D. Reproductive ecology. 



1. Types of reproduction: Details of the 



breeding system are unknown. Pollinators 

 ( Bombus spp . ) were observed visiting 

 flowering heads at several locations. It is 

 likely that there is some outcrossing as 

 well as selfing, as the insects were observed 

 to indiscriminately fly between the heads of 

 the same and different plants while foraging. 



No evidence of asexual reproduction was 

 observed during field studies. The extent 

 to which apomixis occurs in the genus is 

 unknown . 



2. Pollination. 



a. Mechanisms: By insects, as discussed 

 above, and to a limited extent possibly 

 by se 1 f i ng . 



b. Specific known pollinators: As noted, 

 Bombus spp. (bumblebees) were observed 

 visiting the heads at several locations. 



c . 



Other suspected pollinators: None 



