suggests that the habitat requirements of the species 

 are quite specific and may relate to the occurrence of 

 a suitable mycobiont. 



3. REPRODUCTIVE BIOLOGY 



a. TYPE OF REPRODUCTION: Sexual. 



b. POLLINATION BIOLOGY: Nectar accumulates by 

 adhesion in the small spaces bounded by the ovary 

 and the sepals. Bumblebees are the primary known 

 pollinators, Psithyrus insularis and Bombus 

 mixtus . Often there is more than one floral axis 

 per root mass and more than several flowers per 

 axis which constitutes a significant reward for 

 pollinators (Wallace 1977). 



G. POPULATION ECOLOGY 



1. BIOLOGICAL INTERACTIONS 



a. EPIPARASITISM: Allotropa virgata indirectly 

 parasitizes pines and perhaps Douglas-fir via 

 connecting mycelia of mycorrhizal fungi. This 

 epiparasitism is relatively common in the plant 

 kingdom, occurring in at least 7 families, 51 

 genera, and approximately 400 species (Furman and 

 Trappe 1971) . Studies of Monotropa and Hypopitys 

 show that they are unable to survive without a 

 fungal associate (Furman and Trappe 1971) . They 

 are best regarded as highly specialized and are 

 the most dependent component of an anatomically- 

 linked system of interacting plants. Materials 

 move from the green component to the 

 achlorophyllous component and vice versa (Furman 

 and Trappe 1971). This is likely true for A. 

 virgata as well. 



a. COMPETITION: In Montana, A. virgata does not occur 

 often in areas with a high percentage of 

 understory cover. It obviously does not compete 

 for light but may be affected by competition for 

 water or soil nutrients, although it derives much 

 of these from the photosynthetic tree and 

 mycorrhizal fungus. 



b. HERBIVORY: Grazing of A. virgata stalks by large 

 ungulates has been observed. 



