8 



1. REGIONAL CLIMATE: The H. macronema population 

 occurs in a region of Montana that is generally 

 dominated by dry, continental weather conditions. 

 Much of the yearly precipitation falls as rain or 

 wet snow in May and June, with large convective 

 storms providing the mid- and late summer 

 moisture. Winters are cold and dry, with 

 precipitation occurring mostly in the form of 

 snow. The nearest long term climatological 

 station is at Divide, approximately 23 miles (36 

 km) northeast of Storm Peak. The weather station 

 at Divide (elevation 5,406 ft (1648 m) ) is nearly 

 3,500 ft (1,067 m) lower than the plant population 

 at Storm Peak (elevation 8,900 ft (2,712 m) ) . 

 This elevation difference is important because one 

 could expect that the H. macronema population 

 would experience colder temperatures, and could 

 potentially receive 20 inches (50 cm) more 

 precipitation than the mean values given for the 

 station. The mean annual temperature at Divide 

 for the time period 1951-1980 was 40.7° F (4.8° C). 

 The mean maximum temperature for July was 79.4° F 

 (26.5°C), while the mean minimum temperature for 

 January was 8.5° F (-13.2° C) . Mean annual 

 precipitation was 12.39 in (30.9 cm), with the 

 highest mean precipitation occurring in the months 

 of May and June (U.S. Department of Commerce 

 1982) . 



P. POPULATION DEMOGRAPHY AND BIOLOGY 



1. PHENOLOGY: Hall (1928) states that flowering and 

 fruiting occurs from July through September. This 

 appears compatible with observations of the 

 Montana population, where only 20 percent of the 

 plants were in flower on 29 July 1990. 



2. POPULATION SIZE AND CONDITION: Twenty plants were 

 observed in this population, but areas directly to 

 the east were unsurveyed, and may contain more 

 subpopulations. The population was in good 

 condition. 



3. REPRODUCTIVE BIOLOGY: No information. 

 G. POPULATION ECOLOGY 



1. BIOLOGICAL INTERACTIONS 



a. COMPETITION: There is no information 



available on the competitive ability of H. 

 macronema . However, the population occurs at 



