Long-leaved Aster: Symphyotrichum ascendens (Synonyms: Aster adscendens, Aster ascendens, Aster chilensis ssp. adscendens, Aster chilensis ssp. ascendens) -
Western Meadow Aster: Symphyotrichum campestre (Synonyms: Aster campestris, Aster campestris var. bloomeri, Aster campestris var. campestris) -
California Aster, Common California Aster, Pacific Asterr: Symphyotrichum chilense (Synonyms: Aster chilensis, Aster chilensis ssp. chilensis, Aster chilensis var. chilensis, Symphyotrichum chilense var. chilense) -
Eaton's Aster, Oregon Aster: Symphyotrichum eatonii (Synonym: Aster eatonii) -
Alpine Leafybract Aster, Alpine Leafy Aster, Leafy Aster, Leafy-bract Aster: Symphyotrichum foliaceum var. apricum (Synonym: Aster apricus, Aster foliaceus var. apricus, Aster subspicatus var. apricus) -
Leafy Aster, Leafybract Aster, Parry's Aster: Symphyotrichum foliaceum var. parryi (Synonyms: Aster ascendens var. parryi, Aster diabolicus, Aster foliaceus var. canbyi, Aster foliaceus var. frondeus, Aster foliaceus var. parryi, Aster foliaceus var. subpetiolatus) -
Hall's Aster: Symphyotrichum hallii (Synonyms: Aster chilensis, Aster chilensis ssp. hallii, Aster hallii) -
Henderson's Aster, Kootenai Aster: Symphyotrichum hendersonii (Synonyms: Aster foliaceus, Aster foliaceus var. lyallii, Aster hendersonii) -
Smooth Aster: Symphyotrichum laeve (Synonym: Aster laevis) -
New England Aster: Symphyotrichum novae-angliae (Synonym: Aster novae-angliae) -
Larger Western Mountain Aster: Symphyotrichum spathulatum var. intermedium (Synonyms: Aster occidentalis ssp. intermedius, Aster occidentalis var. intermedius, Aster spathulatus var. intermedius) - Flower heads 10-50. Leaves elliptic to lanceolate. Plants 40-80 cm high.
Western Aster, Western Mountain Aster: Symphyotrichum spathlatum var. spathulatum (Synonyms: Aster ascendens var. fremontii, Aster delectabilis, Aster fremontii, Aster fremontii var. parishii, Aster occidentalis var. delectabilis, Aster occidentalis var. fremontii, Aster occidentalis var. occidentalis, Aster spathulatus var. spathulatus) - Flower heads 3-10. Leaves elliptic to lanceolate. Plants 20-50 cm high.
Western Bog Aster, Western Mountain Aster: Symphyotrichum spathulatum var. yosemitanum (Synonyms: Aster ascendens var. yosemitanus, Aster occidentalis, Aster occidentalis var. yosemitanus, Aster paludicola, Aster yosemitanus) - Flower heads 3-25. Leaves more or less linear. Plants 30-80 cm high.
Douglas Aster, Douglas' Aster: Symphyotrichum subspicatum (Synonyms: Aster bulteri, Aster douglasii, Aster maccallae, Aster subspicatus, Aster subspicatus var. grayi, Aster subspicatus var. subspicatus, Symphyotrichum subspicatum var. grayi) -