The type was collected along the Lolo Trail in Idaho Co., Idaho, on 15 Jun 1806 although Pursh says "On the waters of the Kooskoosky." The expedition was north of Lolo Creek and camped that evening along Eldorado Creek near the mouth of Lunch Creek (Moulton, 1993: 25-27). (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:06/05/1806