Symphyotrichum occidentale var. yosemitanum
Western bog aster
Family: Asteraceae · Type: Herb · Native
Symphyotrichum occidentale var. yosemitanum (Western bog aster) is a native California herb in the Asteraceae family, recognized by narrow linear leaves distinctive among varieties.
Western bog aster is a California native perennial found in the Klamath Ranges, Cascade Range, and Sierra Nevada in high-elevation meadows at 1,200 to 2,100 meters. Flowering from July to September, this plant produces white to lavender daisy-like flowers in clusters of 3 to 25 flower heads. Growing with slender stems 30 to 80 centimeters tall, it forms an upright and somewhat open habit. Its leaves are predominantly narrow and linear, extending alternately along the stem with a characteristic spathulate shape. In meadow environments, this aster creates delicate displays of pale blooming flowers amidst mountain grasslands.
Identification and appearance
Key characters: 10 sympatric species; narrow linear leaves distinctive among varieties
Habitat and range
Habitat: Uncommon. Meadows
Elevation: 1200-2100 m
California counties: Del Norte, Alpine, Mono, Tulare, Siskiyou, Butte, Lassen, Nevada, Tuolumne, Shasta, Fresno, Placer, El Dorado, Mariposa
Outside California: southern Oregon
Bloom period
Symphyotrichum occidentale var. yosemitanum blooms Jul-Sep.
How to tell it apart
vs Corethrogyne: Corethrogyne has distinctive brown/reddish pappus; Symphyotrichum has white pappus; vs Erigeron: Erigeron has 50+ very thin rays per head; Symphyotrichum has fewer wider rays; vs Eurybia: Eurybia has two-toned bracts (green tips, white bases); Symphyotrichum bracts are all green; vs Aster: Aster is the old name for Symphyotrichum - they're the same plants; vs Dieteria: Dieteria has spinulose-tipped bracts; Symphyotrichum bracts lack spiny tips
Frequently asked questions
Is Symphyotrichum occidentale var. yosemitanum native to California?
Yes. Symphyotrichum occidentale var. yosemitanum is native to California (recorded as native).
When does Symphyotrichum occidentale var. yosemitanum bloom?
Symphyotrichum occidentale var. yosemitanum blooms Jul-Sep.
Where in California does Symphyotrichum occidentale var. yosemitanum grow?
Symphyotrichum occidentale var. yosemitanum occurs in Del Norte, Alpine, Mono, Tulare, Siskiyou, Butte, Lassen, Nevada and other counties, at elevations of 1200-2100 m.
What plant family does Symphyotrichum occidentale var. yosemitanum belong to?
Symphyotrichum occidentale var. yosemitanum is in the Asteraceae family, genus Symphyotrichum.
What habitat does Symphyotrichum occidentale var. yosemitanum grow in?
Symphyotrichum occidentale var. yosemitanum grows in Uncommon. Meadows.
Related species
Other California species in the same genus, family, or bioregion.
- Symphyotrichum sp. — American-aster
- Symphyotrichum spathulatum var. spathulatum — Western mountain aster
- Symphyotrichum subspicatum — Douglas aster
- Symphyotrichum subulatum — Annual saltmarsh aster
- Symphyotrichum subulatum var. elongatum — Eastern annual saltmarsh aster
- Symphyotrichum subulatum var. parviflorum — Eastern annual saltmarsh aster
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.