Few-flowered Aster, Great Northern Aster, Tall Northern Aster, Giant Mountain Aster: Canadanthus modestus (Synonyms: Aster major, Aster modestus, Aster modestus var. major, Aster sayianus, Aster unalaschensis, Aster unalaschensis var. major, Weberaster modestus) -
Elegant Aster: Eucephalus elegans (Synonym: Aster perelegans) -
Engelmann's Aster: Eucephalus engelmannii (Synonym: Aster engelmannii) -
Klickitat Aster: Eucephalus glaucescens (Synonyms: Aster engelmannii var. glaucescens, Aster glaucescens) -
Cascade Aster: Eucephalus ledophyllus var. ledophyllus (Synonyms: Aster ledophyllus var. ledophyllus, Aster ledophyllus var. covillei, Eucephalus ledophyllus var. covillei, Eucephalus ledophyllus) -
Eastern Showy Aster, Eastern Showy Wood-aster, Showy Aster, Western Showy Aster: Eurybia conspicua (Synonym: Aster conspicuus) - Flower heads small with conspicuous outer bracts. Disk flowers yellow and ray flowers violet or bluish. Stem leaves ovate to elliptical, with serrate margins. Stems stiff, erect, and tall.
Entire-leaved Aster, Sticky Aster, Thickstem Aster, Thick-stemmed Aster: Eurybia integrifolia (Synonyms: Aster amplexifolius, Aster integrifolius) -
Arctic Aster, Behring Wood Aster, Siberian Aster, Subalpine Aster: Eurybia merita (Synonyms: Aster meritus, Aster sibericus, Aster sibiricus ssp. meritus, Aster sibiricus var. meritus) -
Rough-leaf Aster, Rough-leaved Aster: Eurybia radulina (Synonym: Aster radulinus) -
Arctic Aster, Behring Wood Aster, Siberian Aster, Subalpine Aster: Eurybia merita (Synonyms Aster meritus, Aster sibiricus var. meritus, Aster sibiricus var. meritus) -
Arctic Aster, Behring Wood Aster, Siberian Aster, Siberian Wood-aster: Eurybia sibirica (Synonyms: Aster sibiricus, Aster sibiricus ssp. sibiricus)
Crag Aster, Lava Aster: Ionactis alpina (Synonym: Aster scopulorum) - Plant to 8 inches tall. Leaves are narrowly elliptical, to 1/2 inch long, crowded along mid stem. The flowers are pink to violet, with a thin yellow central disk and about 8 thin, 1/2 inch long rays.
Alpine Aster, Tundra Aster, Tundra Mountain Aster: Oreostemma alpigenum var. alpigenum (Synonyms: Aster alpigenus, Aster alpigenus ssp. alpigenus, Aster alpigenus var. alpigenus, Haplopappus alpigenus) - A species of moderate altitude to alpine habits in the Cascade Mts., this species may be found on mountain ranges extending eastward from the Cascades and has been included here because of the possibility it might be found in this region.
Alpine Aster, Hayden's Aster, Tundra Aster: Oreostemma alpigenum var. haydenii (Synonyms: Aster alpigenus ssp. haydenii, Aster alpigenus var. haydenii, Aster haydenii, Oreostemma alpigenum ssp. haydenii) -
Intermountain Aster, Longleaf Aster, Long-leaved Aster, Western American Aster, Western Aster: Symphyotrichum ascendens (Synonyms: Aster adscendens, Aster ascendens, Aster chilensis, Aster chilensis ssp. adscendens, Aster chilensis ssp. ascendens, Aster macounii, Aster subgriseus, Virgulaster ascendens) - Flower heads small with conspicuous outer bracts. Stem leaves very short and linear, close to stem. Long narrow basal leaves. Disk flowers yellow and ray flowers pink to lavendar.
Northern Bog Aster, Rush Aster, Slender White Aster: Symphyotrichum boreale (Synonyms: Aster borealis, Aster junciformis, Aster laxiflorus var. borealis) -
Western Meadow Aster: Symphyotrichum campestre (Synonyms: Aster campestris, Aster campestris var. bloomeri, Aster campestris var. campestris, Symphyotrichum campestre var. bloomeri, Symphyotrichum campestre var. campestre) -
Common California Aster, Pacific Aster: Symphyotrichum chilense (Synonyms: Aster chilensis, Aster chilensis ssp. chilensis, Aster chilensis var. chilensis, Symphyotrichum chilense var. chilense) -
Alkali American Aster, Rayless Alkali Aster, Rayless Annual Aster: Symphyotrichum ciliatum (Synonyms: Aster brachyactis, Brachyactis ciliata, Brachyactis ciliata ssp. angustata) -
Hybrid Aster: Symphyotrichum x columbianum (Synonym: Aster columbianus) -
Cusick's Aster, Cusick's American Aster, Leafy Aster: Symphyotrichum cusickii (Synonyms: Aster cusickii, Aster foliaceus, Aster foliaceus var. cusickii, Aster foliaceus var. lyallii) -
Eaton's Aster, Oregon Aster, Whitish Aster: Symphyotrichum bracteolatum (Synonyms: Aster bracteolatus, Aster cordalenus, Aster eatonii, Aster foliaceus var. eatonii, Aster mearnsii, Aster oregonus, Symphyotrichum eatonii) - Plant to 3 1/2 feet in height. The leaves are linear t lanceolate and up to 15 cm long. The dasiy like flowers have white or pink rays and a yellow central disk. The stem may be minutely haired, while the leaves are smooth or rough. The inflorescence is leafy.
Tufted White Prairie Aster, Heath-leaved Aster, Little Gray Aster, Manyflowered Aster, White Heath Aster: Symphyotrichum ericoides var. pansum (Synonyms: Aster ericoides, Aster ericoides ssp. pansus, Aster ericoides var. pansus, Aster falcatus, Aster falcatus var. crassulus, Aster pansus) -
Roug White Prairie Aster, Western Heath Aster: Symphyotrichum falcatum (Synonyms: Aster falcatus, Aster falcatus var. crassulus, Symphyotrichum falcatum var. commutatum, Symphyotrichum falcatum var. crassulum, Symphyotrichum falcatum var. falcatum) -
Alpine Leafybract Aster: Symphyotrichum foliaceum var. apricum (Synonyms: Aster apricus, Aster foliaceus var. apricus, Aster subspicatus var. apricus) -
Alpine Leafybract Aster, Leafy Aster, Leafy Bract Aster: Symphyotrichum foliaceum var. foliaceum (Synonym: Aster foliaceus var. foliaceus, Aster foliaceus var. sublinearis) -
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, Aster frondeus) -
Alkali Aster, Short-rayed Alkali Aster, Short-rayed Aster: Symphyotrichum frondosum (Synonyms: Aster frondosus, Brachyactis frondosa) -
Hall's Aster: Symphyotrichum hallii (Synonyms: Aster chilensis, Aster chilensis ssp. hallii, Aster hallii) -
Jessica's Aster, Palouse Aster: Symphyotrichum jessicae (Synonym: Aster jessicae) -
Smooth Aster, Geyer's Aster: Symphyotrichum laeve var. geyeri (Synonyms: Aster geyeri, Aster laevis, Aster laevis var. geyeri) -
Marsh Aster, Western Willow Aster, White Panicle Aster: Symphyotrichum lanceolatum var. hesperium (Synonyms: Aster hesperius, Aster lanceolatus, Aster lanceolatus ssp. hesperius, Symphyotrichum lanceolatum ssp. hesperium) -
New England Aster: Symphyotrichum novae-angliae (Synonym: Aster novae-angliae) -
Hairy Aster: Symphyotrichum pilosum var. pilosum (Synonym: Aster pilosus var. pilosus) -
Larger Western Mountain Aster: Symphyotrichum spathulatum var. intermedium (Synonyms: Aster spathulatus var. intermedius, Aster occidentalis ssp. intermedius, Aster occidentalis var. intermedius) -
Western Aster, Western Mountain Aster: Symphyotrichum spathulatum var. spathulatum (Synonyms: Aster ascendens var. fremontii, Aster delectabilis, Aster fremontii, Aster fremontii var. parishii, Aster occidentalis, Aster occidentalis var. delectabilis, Aster occidentalis var. fremontii, Aster occidentalis var. occidentalis, Aster occidentalis var. parishii, Aster spathulatus, Aster spathulatus var. spathulatus, Symphyotrichum spathulatum var. fremontii, Tripolium occidentale) -
Douglas' Aster, Douglas's Aster, Spike-like Aster: Symphyotrichum subspicatum var. subspicatum (Synonyms: Aster bulteri, Aster douglasii, Aster maccallae, Aster subspicatus, Aster subspicatus var. grayi, Aster subspicatus var. subspicatus, Symphyotrichum subspicatum var. grayi, Symphyotrichum subspicatum var. subspicatum) -