Publication: Vasc. Pl. Pacific N. W. 2: 22. 1964.
selected vouchers: WTU
Notes: FNA4: "Closely related to inland Abronia villosa. Hybridizes with coastal A. maritima of coastal California and Baja. The variety acutalata is endemic to Washington and adjacent British Columbia. The taxonomy of the varieties is confused and controversial, and has led to reports [KZ] of Abronia umbellata var. breviflora (as subsp. breviflora) from WA, but FNA treats that plant as endemic to southwestern Oregon and the adjacent CA coast. The illustrated BC flora (Douglas et al. 1999) gives var. acutalata (as subsp. acutalata) a mere footnote, assuming it is extirpated from the province, and considers it an "excluded species."