Gravia spinosa (Hook.) Moq. 



Spiny Hcipsage 



NATURAL HERITAGE PROGRAM STATUS: G5/S2 



MONTANA STATUS: Sensitive 



GLOBAL DISTRIBUTION: Central Washington to south-central Montana, south to 

 California, Arizona and New Mexico 



MONTANA DISTRIBUTION: Beaverhead, Big Horn, Carbon and Park counties 



PRYOR MOUNTAINS DESERT DISTRIBUTION: Gravia spinosa is local and 

 uncommon below 1525 m (5000 ft) on the south side of the Prj'or Mountains. Small 

 populations occur in sandy soil in plant associations dominated by Artemisia tridentata . 

 Stipa comata and Agropvron spicatum . 



MANAGEMENT RECOMMENDATIONS: We located only nine populations of a 

 spinosa in the study area, and the majority of these were small. The species is highly 

 palatable to livestock (Welsh et al. 1987) and may decrease with heavy grazing pressure. 

 Gravia spinosa should receive special status on BLM's Miles City District. 



Hvmenoxvs torrevana (Niittall) Parker 



Torrey's Bittorweed 



NATURAL HERITAGE PROGRAM STATUS: G4/S3 



MONTANA STATUS: Limited Distribution 



GLOBAL DISTRIBUTION: South-central Montana, central Wyominu and northern 

 Utah 



MONTANA DISTRIBUTION: Soulhern Carbon County counties 



PRYOR MOUNTAINS DESERT DIS TRIBU TION: Hvmenoxvs torrevana is locally 

 common between 1370 and 2440 m (4500 and 8000 ft) on the south and west slopes of 

 the Pryor Mountains. Numerous small to large populations occur on limestone-derived 

 soil in all montane communities including juniper woodlands, mountain mahogany 

 woodland and cushion plant grasslands. 



23 



