Symphyotrichum occidentale var. intermedius
Larger western mountain aster
Family: Asteraceae · Type: Herb · Native
Symphyotrichum occidentale var. intermedius (Larger western mountain aster) is a native California herb in the Asteraceae family, recognized by taller with more numerous heads than related varieties.
Larger western mountain aster is a California native perennial found in northwestern California, the Cascade Range, Sierra Nevada, and Great Basin in mountain meadows at elevations of 1,200 to 2,000 meters. Flowering from June to August, this plant produces white to lavender flowers in clusters of 10 to 50 heads. Growing with erect stems 40 to 80 centimeters tall, it forms dense clusters in open meadow environments. Its leaves are distinctively lanceolate to narrowly elliptic, arranged alternately along the stem, providing a delicate texture to the plant's overall appearance. The numerous flower heads create a soft, billowing effect characteristic of mountain aster species.
Identification and appearance
Key characters: 11 sympatric species; taller with more numerous heads than related varieties
Habitat and range
Habitat: Meadows
Elevation: 1200-2000 m
Outside California: to British Columbia, Idaho, Nevada
Bloom period
Symphyotrichum occidentale var. intermedius blooms Jun-Aug.
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. intermedius native to California?
Yes. Symphyotrichum occidentale var. intermedius is native to California (recorded as native).
When does Symphyotrichum occidentale var. intermedius bloom?
Symphyotrichum occidentale var. intermedius blooms Jun-Aug.
What plant family does Symphyotrichum occidentale var. intermedius belong to?
Symphyotrichum occidentale var. intermedius is in the Asteraceae family, genus Symphyotrichum.
What habitat does Symphyotrichum occidentale var. intermedius grow in?
Symphyotrichum occidentale var. intermedius grows in Meadows.
Related species
Other California species in the same genus, family, or bioregion.
- Symphyotrichum occidentale var. occidentale
- Symphyotrichum occidentale var. yosemitanum — Western bog aster
- Symphyotrichum sp. — American-aster
- Symphyotrichum spathulatum var. spathulatum — Western mountain aster
- Symphyotrichum subspicatum — Douglas aster
- Symphyotrichum subulatum — Annual saltmarsh aster
Sources: Jepson eFlora · 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.