calcareous soils. In a discussion of ecological "varieties" of C. calceolus in Correll 

 (1950), "var." parviflorum is considered especially difficult to cultivate due to its strict 

 requirements of soil pH, moisture, and temperature. On the KNF, CL calceolus var. 

 parviflorum is known to occur within seven landtypes (Kuennen and Gerhardt 1984); 

 these are landtypes 105, 108, 321, 323, 324, 325, and 355. The most vigorous 

 populations (Brimstone Creek 026, Hidden Lake Area 027, and Magnesia Creek 029) are 

 within landtype 325, with soils classified as typic calciborolls with a high percentage of 

 reprecipitated calcium carbonate; the parent material is alluvium, with the calcium 

 derived from glacial till scoured from Precambrian Siyeh limestone. Landtypes 321, 323, 

 and 324 have soils derived from calcareous glacial till. Where C calceolus var. 

 parviflorum occurs on the alluvial landtypes 105 and 108, the sites are adjacent to and 

 downstream from landtype 323, and reprecipitated calcium is usually evident in the soil. 

 One population site (Jumbo Lake .023) occurs within the landtype 355 mapping unit 

 which has soils which are not noted as being calcareous, however, this is thought to be an 

 artifact of the mapping precision because a highly calcareous horizon is noted on the 

 Element Occurrence Record (Appendix A). In fact, it is likely that more precise mapping 

 would result in many of the sites being reclassified as landtype 325, the type which most 

 closely describes the soils where C. calceolus var. parviflorum grows. Nearly all 

 occurrences are in drainages, usually mapped as glacial till, which are downslope from or 

 surrounded by the main body of the Helena formation as mapped by Harrison et al. 

 (1992). This formation, which is differentiated from the traditional Siyeh formation, 

 consists of dolomites and dolomitic siltites. 



4. Climate factors: Cypripedium calceolus var. parviflorum has a broad distribution both 



north and south of Montana, and within the state it occurs both east and west of the 

 Continental Divide with climate regimes ranging from humid to semi-arid. Its moisture 

 requirements are generally met by a stable, cool, groundwater discharge which 

 compensates for macroclimate differences. Data from the climatological station at 

 Fortine (National Oceanic and Atmospheric Administration 1982) at 3,000 feet elevation 

 characterize the climate where the taxon is concentrated on the Fortine District. From 

 1951 to 1980 the mean temperature normals range from 19.8° F in January to 63.8° F in 

 July and the normal annual precipitation was 17.25 inches. The sites near Libby Dam are 

 characterized by data from the closest station in Libby at 2,080 feet. Mean temperature 

 normals ranged from 22.7 °F in January to 66.7° F in July and normal annual 

 precipitation was 18.66 inches. 



F. Population demography and biology 



1 . Phenology: On the KNF, flowering is in late May to early July and fruit are produced in 

 July through August. Cypripedium calceolus var. parviflorum is reported as flowering 

 somewhat earlier than C^ passerinum (Lesica and Shelly 1991), but on the KNF where 

 they grow together they were flowering concurrently in 1995. Flowers are needed for 

 reliable identification, thus, occurrences found late in the season in fruit (e.g. Lime Creek 

 .055) need to be revisited earlier in the season to verify their identity. 



2. Population size and condition: Evaluation of population numbers is difficult because 

 there has not been consistent distinction between aerial stems, which may be clonal 

 (ramets), and individual plants or clumps of stems, presumably reproduced by seeds 

 (genets). A conservative approach is to consider the following numbers in terms of aerial 

 stems; the number of genets in a population may be considerably less (see discussion of 

 vegetative reproduction below). Estimated population numbers in Montana range from 

 two to over 1,000 stems. Most populations in the state consist of fewer than 200 stems, 

 and many have fewer than 50. Some of the largest populations are found on the Lewis 



