I . SUMMARY 



Allotropa virqata occurs primarily west of the Cascade and Sierra 

 Nevada mountains from British Columbia to northern California. 

 Disjunct populations occur in southwestern Montana and adjacent Idaho. 

 The plant is a Region 1 sensitive species and is ranked G4/S1 in both 

 Montana and Idaho. The first record of the species from Montana was in 

 1974. Subsequent survey work has located 27 populations in 

 southwestern Montana on the Beaverhead, Bitterroot and Deerlodge 

 national forests, including some timber sale blocks. 



In Montana, Allotropa virqata populations occur most often in 

 Abies lasiocarpa/Xerophyllum tenax or Abies lasiocarpa/Vaccinium 

 scoparium habitat types. The dominant canopy tree is usually Pinus 

 contorta with Pseudotsuqa menziesii often co-dominant. Stand age is 

 120-330 years with an average of about 200 years. Understory 

 vegetation cover at these sites is generally sparse. Populations 

 generally occur on moderate slopes and southerly aspects are most 

 common. 



Allotropa virqata is obligately dependent on an association with 

 a mycorrhizal fungus which in turn is associated with a tree, likely 

 lodgepole pine ( Pinus contorta ) or Douglas-fir ( Pseudotsuqa 

 menziesii ) . It is thus, highly sensitive to the loss of these canopy 

 trees whether through timber harvest or stand-replacing fire. Several 

 of the current locations of Allotropa virqata are within proposed 

 timber sales. 



Populations of Allotropa virqata are characteristically small 

 with most being fewer than 100 stalks. Many populations consist of 

 fewer than 5 stalks. These small populations are often scattered 

 across the landscape in large areas of seemingly suitable habitat. 

 This suggests that the habitat requirements of the species are quite 

 specific and may relate to the occurrence of a suitable fungal 

 partner. 



Management planning should take all Montana sites into account in 

 order to maintain viable populations. Field surveys should be 

 continued for additional populations on the Beaverhead, Bitterroot and 

 Deerlodge National Forests. Monitoring of existing populations should 

 be continued and expanded. Additionally, the information gathered in 

 the survey and monitoring activities recommended above should be used 

 to prepare a species management guide for Allotropa virqata . The guide 

 should be prepared in cooperation with the Nez Perce National Forest 

 and the Idaho Conservation Data Center and should include the Idaho 

 populations in the strategy. 



