62 



peninsula approximately 150 square meters in area, 

 and in meadows close to the peninsula. 



3. BIOLOGICAL INTERACTIONS: It is difficult to define 

 the factors restricting the distribution of 

 Castilleia qracillima . Competition is not easily 

 observed, and soil moisture is more likely to be a 

 limiting factor. Castilleia s are subject to 

 herbivory by noctuid larvae; however, C. qracillima 

 does not seem to be as heavily fed upon as many 

 other species (pers. obs.). Hybridization is 

 common amongst Castilleia species, and is possibly 

 responsible for some of the more robust, non- 

 rhizomatous members of the observed populations. 



G. LAND OWNERSHIP: Along Grayling Creek, Castilleia 



qracillima occurs on both U.S. Forest Service lands and 

 Yellowstone National Park lands. The population at 

 Snowflake Springs may occur at least partially on 

 private lands that border the springs to the north. The 

 smaller subpopulations, along the Gallatin River toward 

 the Park boundary, are on Gallatin National Forest lands 

 or State of Montana lands (Gallatin Wildlife Management 

 Area) . 



II. ASSESSMENT AND MANAGEMENT RECOMMENDATIONS 



A. THREATS TO POPULATIONS: Populations of C. qracillima 

 appear to be stable at this time. The most likely 

 threats would stem from environmental rather than man- 

 caused events. Disturbance and re-establishment 

 probably occur at relatively frequent intervals due to 

 the stream and river bank habitats where populations 

 occur. 



B. RECOMMENDATIONS FOR MAINTAINING VIABLE POPULATIONS: 

 Recreation in the form of fishing is the main use of the 

 two Gallatin National Forest sites where C. qracillima 

 is known to occur. No altered management practices seem 

 to be called for at this time. Should further surveys 

 reveal populations in drainages where livestock grazing 

 takes place, monitoring of such populations would be 

 called for to assess whether or not livestock use posed 

 a threat. 



C. RECOMMENDATION FOR FURTHER ASSESSMENT: Castilleia 

 qracillima occurs in Yellowstone National Park in 

 saturated meadow habitats not so closely associated with 

 major drainages. Similar habitats in the southern 

 regions of the Gallatin National Forest may also support 

 populations of C. qracillima . Potential sites could be 

 located with the use of topographic maps, and 

 subsequently surveyed. 



