VI. RESULTS 



The results from the sensitive plant species inventory 

 yielded data that confirmed that the Centennial Valley is a 

 highly diverse area. The data within Table 2 and presented in 

 Figure 2 are a compilation of the rare flora that have been 

 documented in Centennial Valley. The species information that 

 follows represents detailed data gathered from BLM-administered 

 land on the following plant species: Astragalus ceramicus var. 

 apus . Carex vallicola , Cryptantha fendleri . Erioqonum 

 ovalif olium var. nevadense, Ipomopsis congesta ssp. crebif olia , 

 Penstemon whippleanus , Senecio debilis , Sphaeralcea munroana and 

 Thelypodium sagittatum ssp sagittatum . In addition, Draba 

 globosa was collected by a cooperating researcher, and sensitive 

 plant survey forms were submitted by the author and a cooperating 

 researcher on four additional state species of special concern 

 after this report was conveyed in final form to the Montana 

 Natural Heritage Program. The four additional species include 

 Astragalus argophyllus var. argophyllus , Astragalus lentinginosus 

 var. salinus , Astragalus terminalis and a new species addition to 

 the state flora, Stellaria iamesiana . The results represent new 

 information on fourteen species, with detailed treatment for the 

 first nine. 



In addition, there were previous documentations of the 

 following plant species on BLM-administered land: Balsamorhiza 

 macrophylla , Carex parryana ssp. idahoa , Elymus flavescens , 

 Gentiana aquatica , Oenothera pallida var. idahoensis and 

 Thalictrum alpinum ; for a total of twenty rare taxa documented on 

 BLM lands. All new or revisited records and pre-existing records 

 are depicted in Figure 2, pocket map. 



Of the 39 Centennial Valley rare species, ten are 

 recommended dropped from BLM proposed sensitive or watch 

 consideration, but eleven are recommended for sensitive 

 consideration and eleven for watch consideration. 



The field season of 1993 was often interrupted due to 

 unseasonally cool temperatures and high precipitation. These 

 factors significantly influenced the extent of the area surveyed, 

 which places even more importance on the high numbers of species 

 documented in an abbreviated field season. The significant 

 number of occurrences of rare plant species documented in a 

 shortened field season, indicates a need for further survey work 

 in the Centennial Valley to determine the extent of biodiversity 

 in this region. These results strongly indicate that further 

 survey work would reveal more element occurrences of rare plant 

 species. 



Results and recommendations based on this work are 

 summarized on the Table 2 (next page) . Information on individual 

 species follows alphabetically, beginning with nine species 

 described in detail, followed by five species whose status in the 

 Centennial Valley is briefly summarized based on information 

 which came in late. Appendix B includes printouts of all species 

 recommended for further consideration, and Appendix C includes 

 maps of new or revisited records. 



