twisted petals. When they are learned, species of Cypripedium on the KNF can be 

 recognized vegetatively or in fruit, but may be difficult to determine to the species level. 

 Cypripedium montanum is often more robust, with wider leaves than C passerinum or C 

 calceolus var. parviflorum and usually has more flowers (or fruits) per stem, often more 

 than two. On the KNF Cypripedium passerinum usually has lighter colored leaves, is 

 more densely silky pubescent, and is more strictly single flowered than C calceolus var. 

 parviflorum . 



D. Geographical distribution 



1. Range: Northern North America, from Alaska to Quebec south to southeastern British 

 Columbia, northern Montana, and Lake Superior (Hitchcock and Cronquist 1973). 

 Cypripedium passerinum is one of the few orchids which grows above the Arctic Circle 

 (Luer 1975). 



2. Montana distribution: Cypripedium passerinum has a peripheral distribution in 

 northwestern Montana, the only place where it grows south of the Canadian border (Luer 

 1975). There are now 27 occurrences in the state entered in the Biological Conservation 

 Database (Figure 2 inset). These are in Flathead (8 occurrences), Lake (4), Lewis and 

 Clark (3), Lincoln (5), Pondera (2), Powell (3), and Teton (2) counties. One of these 

 occurrences, at Columbia Falls, is historical, represented only by an 1 894 collection. 

 These numbers do not include possible 1995 discoveries outside the KNF. 



3. Occurrences on the Kootenai National Forest 



a. Current sites: Cypripedium passerinum was first found on the KNF in 1992 (Hoitsma 

 1992) and is now known from six sites, all on the Fortine Ranger District (Figure 2). 

 Two of these occurrences, Brimstone Creek (025) and Magnesia Fen (026), were new 

 discoveries in 1995. Element Occurrence Records and topographic maps showing the 

 precise locations of these populations are provided in Appendix A. 



b. Historical sites: none 



c. Unverified/undocumented sites: none 



d. Areas surveyed but species not located: See listing under this heading for Cypripedium 

 calceolus var. parviflorum . 



E. Habitat 



1. Associated vegetation: In Montana, Cypripedium passerinum is nearly always 



associated with spruce habitat types, usually on edges and ecotones with wetland features 

 such as fens, swamps, deciduous riparian thickets, lakesides, and springs. On the KNF, 

 the dominant tree species may be Picea engelmannii . R glauca . or hybrids, and habitats 

 include the Picea/ Clintonia uniflora . Picea/Equisetum arvense (Pfister et al. 1977) and 

 Picea/Cornus stolonifera (Hanson et al. 1 995) types. Deciduous tree species at some sites 

 include Betula papyrifera and Populus balsamifera . Common shrubs, which may 

 contribute as much or more canopy cover than the dominant trees in these habitats, 

 include Alnus viridis . Betula occidentalis or Betula glandulosa . Cornus stolonifera . 

 Lonicera involucrata . and Rhamnus alnifolia . The sites with Cypripedium passerinum on 

 the KNF have high coverage by a diversity of wet site forbs and the conspicuous presence 

 of other orchids. At or nearby five of the six sites, two other sensitive orchids, 

 Cypripedium calceolus var parviflorum and Orchis rotundifolia also occur. Thus, known 



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