According to the label, type material of this species was collected on 1 Jul 1806. The actual date was probably 2 Jul as Lewis "found serveral other uncommon plant specemines of which I preserved" (Moulton, 1993: 79). Lewis also wrote "I found two speceis of native clover here, the one with a very narrow leaf and a pale red flower, the other nearly as luxouriant as our red clover with a white flower the leaf and blume of the latter are proportionably large." Moulton (1993: 80) suggests the first of the two is Trifolium microcephalum. Pursh gives the location as "On the banks of Clarck's river . . . July" and the label has "Valley of Clarks R." We presume the collection was made in the Bitterroot Valley at or near Traveler's Rest. (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:07/02/1806