Lewis makes a reference to this species on 25 Jun 1806 (Moulton. 1993: 50-51) but the specimen is dated 27 Jun (Moulton, 1993: 55-59). On both days the expedition was on the Lolo Trail in Idaho Co., Idaho. The illustration published by Pursh probably was based on sketches made for Lewis by Pursh while the latter was still in Philadelphia (Rossi & Schuyler, 1993). (The Lewis & Clark Herbarium Digital Imagery Study Set, ANSP, 2002) On deposit at the Academy of Natural Sciences, Philadelphia Collected by:Meriwether Lewis & William Clark Collection date:06/27/1806