STATUS 



SCIENTIFIC NAME: Cirsium lonqistylum Moore & Frankton. 



COMMON NAME: long-styled thistle. 



FEDERAL STATUS: 02 



FOREST SERVICE STATUS: None. In 1991, Cirsium lonqistylum 

 was removed from the Watch List of sensitive species for 

 Region 1 of the U.S. Forest Service due to abundance. 



FIELD SURVEY 



While making collections of C. lonqistylum for the taxonomic 

 study in 1991, a brief survey of the Highwood Mountains was 

 completed. The introduced species Cirsium arvense and C. vulqare 

 were both present here, but C. lonqistylum was not observed. It 

 is possible that C. lonqistylum is associated with the calcareous 

 soils of the Little Belt, Big Belt and Castle Mountains. The 

 Highwood Mountains on the other hand, are volcanic centers that 

 erupted shonkinite (similar to basalt, but greatly enriched in 

 potassium) and other rocks about 50 million years ago (Alt and 

 Hyndman 1986) . 



TAXONOMIC STUDIES 



INTRODUCTION: Several Cirsium collections from the Little 

 Belt Mountains and the Sawtooth Range were sent to Dr. 

 Arthur Cronquist (a specialist in the Asteraceae=Sunf lower 

 Family) for verification in the winter of 1990-1991. The 

 Sawtooth Range collection, Schassberqer (402) . NY, was 

 verified as C. hooker ianum . However, of the two sent from 

 the Little Belt Mountains ( Schassberqer (403) , NY, Belt 

 Park; Schassberqer (397) , NY, Thornquist Gulch) , Dr. 

 Cronquist (1991) felt that the Thornquist Gulch collection 

 "would seem to loe C. lonqistylum . " whereas the collection 

 from Belt Park "looks to me like C. hooker ianum . " He went 

 on to state that "I included C. lonqistylum , with some 

 reluctance, in the single-volume flora for the Pacific 

 Northwest, but I was uneasy about it then and I remain so 

 now." Close examination by professional botanists of plants 

 from the same population had often revealed a great deal of 

 variability in the expansion of the involucral bract, a key 

 character used in the identification of C. lonqistvlum . 



In the hopes that a more definitive conclusion might be 

 reached, it was determined that a large number of specimens 

 (preferably with duplicates) from sites across the range of 

 the species should be sent to Dr. Cronquist for careful 

 examination. 



