Physocarpus malvaceus (mallow ninebark) 

 Selaginella wallacei (Wallace selaginella) 



2. TOPOGRAPHY: In Montana, all of the L. bicolor 

 var. bicolor populations occur on steep, rocky 

 scree slopes. These sites often have a more 

 southerly or easterly aspect. The individual 

 plants of the Berray Trail (001) subpopulations 

 were established in the crevices of rocky outcrops 

 and on steep scree slopes. 



3. SOIL RELATIONSHIPS: In Montana, populations of L, 

 bicolor var. bicolor occur on mineral soils that 

 appear to contain little or no organic matter. 

 This species possesses a stout root system, which 

 can grow deep into rock crevices. This allows 

 individuals to become established on rocky scarps 

 or on moving scree slopes (pers. obs.). 



4. REGIONAL CLIMATE: The mountainous region of 

 northwestern Montana is dominated by a cool 

 Pacific temperate climate. Winters in this region 

 are cold and snowy, and the summers are warm and 

 rainy. The highest amounts of precipitation 

 accumulate during the period from November through 

 January in the form of snow. The weather 

 collection site at Trout Creek Ranger Station is 

 approximately 15 miles east of the Bull River 

 valley, and at an elevation of 2,370 feet (the L. 

 bicolor var. bicolor subpopulations are at 4,000 

 to 4,700 feet in elevation). For the period from 

 1951-1980, the July mean temperature at Trout 

 Creek Ranger Station was 65.0° F, the January mean 

 was 24.1° F, and the mean annual precipitation was 

 30.49 inches (U.S. Departtnent of Commerce 1982). 



F. POPULATION DEMOGRAPHY, BIOLOGY AND SPECIATION 



1. PHENOLOGY: Populations of L. bicolor var. bicolor 

 in the Bull River valley may begin to flower in 

 late May to early June, and bear immature fruits 

 by the end of June. According to Schlessman 

 (1984) , this species (across its range) flowers 

 from April through June, with fruits maturing from 

 late April to early August. 



2. POPULATION SIZE AND CONDITION: The two observed 

 subpopulations in the Bull River valley 

 collectively contained fewer than 1,000 individual 

 plants. Although not large, the subpopulations 

 did appear to be in good condition, with numerous 

 fruiting individuals. 



