midslopes and lower benches at the upper end of draws with well-developed 

 meadow communities (i.e. below a spring northeast of Poker Jim Butte), as 

 well as above localized settings with groundwater seepage (i.e. the Home Butte 

 wetland thickets). 



3. SOIL RELATIONSHIPS: Soils are dark, silty and sandy loams that remain 



moist through most of the growing season and are often temporarily saturated 

 in early spring. Soils usually contained a rich humus layer and pine duff 



POPULATION BIOLOGY AND DEMOGRAPHY 



1. PHENOLOGY: Fruits (perigynia) were beginning to mature in late June 

 during the relatively cool, somewhat late 1995 growing season. Carex torreyi 

 has been collected from mid June through July in Montana. It readily looses 

 its fruits and cannot be identified with certainty when it dries late in the 

 growing season. 



2. POPULATION SIZE AND CONDITION: Population sizes in the study 

 area are the largest known in Montana, ranging from 5-1000+. All have fewer 

 than 1 00 plants, except for the large population near the East Fork of Otter 

 Creek. Rangewide the species has been characterized as "rare and local" in dry 

 foothills settings (Hermann 1970). Identification of individual plants can be 

 difficult due to the loosely cespitose growth form. Areas occupied range in 

 size from 2 to 3 acres, but the plants are concentrated within smaller locales. 



3. REPRODUCTIVE BIOLOGY 



a. TYPE OF REPRODUCTION: Most clumps had multiple flowering 

 stalks. Carex torreyi also reproduces vegetatively via rootstock 

 offshoots on the perimeter of cespitose clumps. 



b. POLLINATION BIOLOGY: Outcrossing by wind pollination is 

 common in the genus. 



c. SEED DISPERSAL AND BIOLOGY: Unknown. 

 POPULATION ECOLOGY 



1. COMPETITION: Torrey's sedge occupies habitat that is widely subject to 



exotic species invasion, including species which often crowd out native species 

 (Bromus tectorum, Poapratensis). Its population numbers are consistently 

 low under high competition settings, where it persists only at the edges of the 

 microrelief and ecotone. 



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