The duplicate of the lectotype, a Lambert sheet, would normally be the more appropriate choice as the lectotype given that this was what Pursh had before him when he prepared the manuscript. However, the specimen on PH-LC 47 is badly damaged and thus we have selected the American Philosophical Society sheet (PH-LC 46) as the lectotype. The type material was collected at the mouth of the Sandy River along the Columbia River in Multnomah Co., Oregon, on 1 Apr 1806. Neither Lewis nor Clark mentions finding the species (Moulton, 1991: 48-53). (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:04/01/1806