This species keys to A. eatonii in Hitchcock though there are several characteristics that don't fit that description. Some keys call this A. chilense though apparently A. c. is strictly coastal in WA. This is probably a result of local hybridization with Aster (Symphyotrichum) subspicatus, possibly A. hallii and/or A. chilense. The following is taken from eflora.com: "Symphyotrichum subspicatum is a weedy, highly polyploid species, probably of allopolyploid derivation from different combinations of species including S. chilense, S. eatonii, S. foliaceum, S. laeve, and S. spathulatum. Hybrids with S. hallii are known from western Oregon. The species passes into S. foliaceum in southeastern Alaska."