Publication: J. Arnold Arbor. 29: 212. 1948.
selected vouchers: WTU
Notes: FNA8: "Variety pulchellum is the most widespread and common variant of the species. It ranges from south-eastern Alaska and western Canada, to southeastern Manitoba, to Lassen County, California, northern and eastern Arizona, New Mexico, and northern Mexico. Scattered populations are found in western North Dakota (Burke County) and in western Nebraska (Morrill County). A collection at Fort Lewis, Thurston County, Washington (D. Thysell 705, WTU), may be an introduction."