Stipa viridula*^ 

 Townsendia florifer * 



The preceding infomiation does not include the associated species at the other Madison County 

 site, which is in an intennontane valleybottom setting along unimproved roads where it may be 

 accidental. The primary associated species at this other site include Stipa comata, Agropyron 

 smithii, Chrysothamnus nauseosus, and Sporobolus airoides. 



In the Ruby Range, it was not sympatric with common Indian ricegrass (Oryzopsis hymenoides), 

 though the latter is in nearby montane settings. There was local overlap between these ricegrass 

 species in all Beaverhead County sites documented in 1995, but not in any of the new 1996 sites. 

 Its study area habitat overlaps with that of Townsendia florifer as shown in Appendix E. 



POPULATION INFORMATION: The study area population numbers were estimated to be at 

 least in the 100,000 order of magnitude, signifying the largest known population. Individuals are 

 locally common in the arid grassland setting, in relatively high densities approaching 1 every 

 meter. All other recent records document it in much lower densities and frequency. The next 

 largest population is also in the Dillon Resource Area on Hemiebirry Ridge. 



Mature plants ha^'e 1-few spikes per basal tuft, and the basal tufts are taken to represent discrete 

 bunchgrass individuals. In southwestern Montana, the spikes emerge and expand in mid- June, 

 and the inflorescence retains most seeds into July but readily shed seeds once cured. In Pondera 

 County, it appeared that plants were about three weeks later in phenology compared to southwest 

 Montana. 



MANAGEMENT CONSIDERATIONS: Like common indian ricegrass, contracted ricegrass 

 is considered to be a decreaser under livestock grazing (Fertig 1994). Its presence is taken to 

 indicate rangeland in fair or better range condition. Its study area habitat appears to be in 

 excellent condition, though the vegetation is extremely sparse and has low productivity. 

 Nevertheless, it is located close to water, and potentially affected by allotment management 

 actions. It might be appropriate to consider as a pasture indicator species, but its recommended 

 deletion from BLM watch status would preclude special management provisions. 



It does not appear to be a good competitor, and exotic species invasion poses threats. Because of 

 its low competitive ability, it occurs elsewhere at localized natural or unnatural settings for early 

 plant succession e.g., around rock outcrops or along roadside rights-of-way. 



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