[Asters: The Genera Canadanthus, Eucephalus, Eurybia, Oreostemma and Symphyotrichum Found East of the Cascade Mountains of Oregon and Washington]

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

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)

Western mountain aster growing along Forest Service Road #16 in Summit Prairie, Malheur National Forest........August 20, 2011.

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)

Western mountain aster growing along Forest Service Road #16 in Summit Prairie, Malheur National Forest........August 20, 2011. Similar to leafybract aster (Symphyotrichum parryi var. parryi), the western mountain aster tends to have narrower and longer stem leaves, narrower involucral bracts, and often, more flower heads than leafybract aster has.

Flower head of 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) - Involucral bracts of 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)

Mid- stem leaf of 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) - 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)

Western mountain aster growing along Forest Service Road #1647 in southeastern Logan Valley, Malheur National Forest........August 4, 2011. Note the prominent white margins of the middle and upper involucral bracts. This individual flower head has fewer and wider rays than the individual pictured below.

Involucral bracts of 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) - 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) - Flower head of 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)

Additional close-up photos of western mountain aster as seen at a large riparian meadow along the south side of the North Loop Road about one mile downhill from the Kiger Gorge Overlook, Steens Mountain, Harney County, Oregon........September 2, 2011. Note the narrower middle and stem leaves, white-margined involucral bracts (middle and upper bracts), and numerous, narrow ray flowers at the margin of the flower head. The similar leafy aster (Symphyotrichum foliaceum var. parryi) also grows at this location but it has middle and lower stem leaves that are broader (wider than 7 mm), more flower heads per stem (usually), fewer and broader rays in the flower head, and involucral bracts that are greener and not white-margined.

Flower head of 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) - Involucral bracts of 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) - 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)

Western mountain aster as seen in a riparian meadow along a small creek along the South Loop Road about one mile west of the East Rim Viewpoint, Steens Mountain........September 20, 2015.

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) - 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) - 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)

Western mountain aster observed along Forest Road 3915 near the headwaters of the North Fork Twelvemile Creek, Fremont-Winema National Forest......July 31, 2020.

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)

Western mountain asters as seen in meadows along the East Fork Lostine River about one-quarter mile upstream from Lost Lake, Eagle Cap Wilderness.........August 4, 2016.
Paul Slichter