The Lewis sheets consist of a single leaf each gathered along the lower Columbia River between Puget's Island and the Cowlitz River on 26 Mar 1806. Both explorers mention the species on numerous occasions (Moulton, 1988, 1990). (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:03/26/1806

Gathered along the lower Columbia River between Puget's Island and the Cowlitz River on 26 Mar 1806. Both explorers mention the species on numerous occasions (Moulton, 1988, 1990). (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:03/26/1806