2. Population demography 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). Throughout Montana, reported population 

 numbers range from 2 to 1,200 aerial stems and areal coverage of the populations ranges 

 from a few square feet up to 15 acres. Relatively large populations are reported from the 

 Rocky Mountain Front, Glacier Park, and the Bob Marshall Wilderness. In contrast, 

 Kootenai National Forest populations are extremely small. The highest number seen (64 

 "plants") was in 1993 at Laughing Water Creek. Hoitsma (1992) first found Cypripedium 

 passerinum on the Kootenai National Forest and observed between 30 and 50 "plants" in 

 each of three populations. In attempts to relocate two of these occurrences in 1995, 1 

 found only a few aerial stems at each site, and was unable to relocate all subpopulations. 

 Also in 1995, Tobias Spribille observed only 15 "plants" at a newly discovered site for 

 the species at Magnesia Creek, and I found just one clump with 3 stems at Brimstone 

 Creek. Census numbers in 1995 may indicate population declines of C. passerinum on 

 the Kootenai National Forest. None of the populations on the Kootenai cover more than 

 one acre. Estimates of population numbers and area are given, as available, for all 

 populations on the KNF in the element occurrence data and size fields of the Element 

 Occurrence Records in Appendix A. 



3. Reproductive biology: The reproductive biology of orchids in general is characterized 

 by complex floral morphologies and mechanisms adapted to cross pollination by insects, 

 and by the production of tiny seeds, potentially in great numbers, which can be dispersed 

 long distances but which are dependent upon fungi for seed germination and seedling 

 development. 



Unlike most orchids and other species of Cypripedium . C passerinum has been shown to 

 be capable of self pollination (Catling 1983). Tobias Spribille pointed out flowers of C 

 passerinum at Laughing Water Creek (024) with ovaries beginning to expand before the 

 flower had apparently opened, possible evidence of self pollination or agamospermy 

 (vegetative production of seeds without fertilization), and I observed this condition at 

 other sites on the KNF. Bernhardt (1990) states that the small lip size of C passerinum 

 makes it dependent on small bees for pollination, but Shelly (1980) observed no 

 pollinator visitation to plants on the Flathead and Lewis and Clark National Forests, again 

 suggesting self pollination. Self pollination, like vegetative reproduction, restricts gene 

 flow leading to adaptation and evolution (Catling 1983), but may be important for the 

 perpetuation of small isolated populations like those of C. passerinum on the KNF. The 

 breeding system of C^ passerinum is probably a mixture of self and cross pollination. 



Germination of terrestrial orchid seeds depends on penetration by fungal hyphae, and the 

 plants grow underground as colorless mycorhizomes for a period of time before 

 producing photosynthetic tissue (Wells 1981). 



Cypripedium passerinum can also reproduce vegetatively by rhizomes. These have been 

 described as slender and creeping (Correll 1950) or as short (Luer 1975). The distance of 

 potential spread by rhizomes remains unclear; plants which I observed on the KNF in 

 1995 grew in small compact clumps with just a few stems. Vegetative reproduction 

 allows a population to persist and spread locally, but does not alone supply genetic 

 variation which allows the population to adapt or seeds for long distance migration. 



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