When Steyermark (1934: 479) indicated a type for this species, he cited Lewis material at PH collected "near the old Maha village" (e.g., PH-LC 100 and PH-LC 101). However, he annotated a third sheet (PH-LC 102) without any label information as the "Type collection." Based on his conflicting statement, it is ambiguous as to what he had in mind. PH-LC 100 is annotated with an original Lewis label; this is numbered "40" and corresponds to Lewis 40 in the plant list Lewis sent to Thomas Jefferson (Moulton, 1987a: 451-472). Pursh annotated the American Philosophical Society sheet "Anonymus balsamifera" and questionably suggests the plant belonged to a new genus. The Lambert Herbarium sheet we have designated as the lectotype, PH-LC 101, is annotated with the same Pursh label as "Anonymus balsamifera" except that the notation about the plant being a new genus is not present. The two, centrally positioned specimens on this sheet seemingly are further annotated "N America Lewis & Clarck" by Lambert. The third sheet, PH-LC 102, is a mixed sheet consisting of an 1811 Thomas Nuttall specimen (left-hand specimen) and probably a Lewis and Clark element. Steyermark apparently felt, and in our view correctly so, that the large specimen on the right-hand side of the sheet went with Lambert's Lewis and Clark annotation. There is a small fragment in the upper center of the sheet that is without attribution. It probably goes with the Lewis and Clark specimen on the right, but this is only an assumption. PH-LC 101 appears to be a mixed collection. The fragments here designated the lectotype match closely the fragment found on PH-LC 100, an authentic Lewis collection. The two lateral fragments on 101 are marked "2" in pencil. This may have been written by Meehan, but why is uncertain. Pursh reports he saw both dried specimens and living material. Could these be fragments out of the garden? PH-LC 102 is definitely a mixed collection as noted above, and the two outermost fragments on 101 are similar to the Nuttall fragment on 102. We suspect the two small, flowering fragments on 101 are additional pieces of the 1811 Nuttall collection. The lectotype was collected at Tonwontonga, a large Indian village in Dakota Co., Nebraska, on 17 Aug 1804 (1986: 486-488). Cronquist (in Cronquist et al., 1994: 256) designates "Lewis 40" as the "holotype," and on the surface this would seem to imply PH-LC 100, but the location data and the number go equally with both PH-LC 100 and PH-LC 101, and therefore he failed to select a specific sheet. Steyermark annotates PH-LC 102 as the "Type collection," but there is no indication this is a duplicate of Lewis 40 nor is there any indication where the specimen was collected. Finally, there is some question as to the integrity of PH-LC 101. Accordingly, we select as the lectotype the two central fragments on the Lambert sheet Pursh had with him in London when he proposed the name. There is no question that this is authentic material. (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:08/17/1804