Thennopsis rhombifolia 

 ToMusendia hookeri 

 Tragopogon dubius 

 Triodanis perfoUata 



2. TOPOGRAPHY: In the study area, the species was found to be restricted to 

 mid- and lower-slope settings. This placement is probably due to substrate 

 preference rather than to slope position preference because it was usually found 

 on erodible shales (see soil infonnation, below) capped by more 

 erosion-resistant layers of sandstone or clinker. The outcrop habitats span a 

 range of elevations and landform settings. 



3. SOIL RELATIONSHIPS: This taxon turned up with high consistency on a 

 fine silt substrate of powdery pale-colored shale. It was also found on a 

 cream-colored shale member and occasionally on gravelly substrates 

 associated with the shales or separate from them. The Custer County 

 collections were made from "sandy upland loam" and from "gumbo soil." All 

 settings represent dry, sedimentary outcrop slopes. 



POPULATION BIOLOGY AND DEMOGRAPHY 



1. PHENOLOGY: Wyoming ballhead gilia was collected in late flower on 23 

 May 1995. Other flowering Montana collections have been made on 17 May 

 and on 6 June. Its ripe fruits dehisce, and only remnants are left by July. 



2. POPULATION SIZE AND CONDITION: Survey of this taxon was 

 conducted by taking actual counts in the center of its habitat and then by 

 extrapolating the results across adjoining potential habitat. This was done in 

 July when it was past flower and relatively inconspicuous, so actual counts and 

 estimates are likely to be low. Actual counts ranged from 20-72 plants, and 

 estimated numbers ranged from 30-200 for a given locale. The high habitat 

 fidelity and recurrence of its outcrop habitat in the dissected study area terrain 

 suggest that numerous subpopulations may exist, creating a scattered 

 megapopulation up and down the drainages. Such likelihood was examined 

 along the Ten Mile Creek drainage, where four occurrences were found along 

 over 6 miles of valley in the same settings. 



3. REPRODUCTIVE BIOLOGY 



a. TYPE OF REPRODUCTION: By seed. 



b. POLLINATION BIOLOGY: Insect-pollinated. 



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