[Asters: The Genera Canadanthus, Eucephalus, Eurybia, Seriocarpus and Symphyotrichum in the Columbia River Gorge of Oregon and Washington]

Larger Western Mountain Aster, Western Aster, Western Mountain Aster

Symphyotrichum spathulatum var. intermedium

Synonyms: Aster occidentalis ssp. occidentalis, Aster occidentalis var. occidentalis, Aster spathulatus var. intermedius

The flower head of Aster occidentalis var. intermedius as found at the mouth of the Deschutes River.........September 3, 2000.

Stem leaves of Larger Western Mountain Aster, Western Aster, Western Mountain Aster: Symphyotrichum spathulatum var. spathulatum (Synonyms: Aster occidentalis ssp. occidentalis, Aster occidentalis var. occidentalis, Aster spathulatus var. intermedius)

The photo at right illustrates the mid to upper stem leaves of Aster occidentalis var. intermedius as found at the mouth of the Deschutes River.........September 3, 2000. Note the narrow leaves.

Characteristics:

Western aster is an erect perennial wildflower arising 20-100 cm from a creeping rhizome. The herbage is generally smooth or without hairs. The lower stem leaves are oblanceolate in shape and petiolate, and they tend to persist into flowering. They may have entire or serrate margins. The middle and upper leaves are narrower with entire margins and measure from 3-15 cm long and 3-15 mm wide. The leaves tend to be 7-20 times longer than they are wide.

The inflorescence is a corymb or cymose panicle of one to many flower heads about 2.5 cm wide. The involucre is 5-7 mm high with obtuse to acutely tipped bracts. The bracts are green and occasional purple margined. Individual bracts are narrowly linear or linear-oblong with short hairs along the margins. The 20-50 rays are about 6-15 mm long and blue, violet or purple in color.

Variety intermedius is much larger and more branched than variety occidentalis with more flower heads arranged in a leafy-bracteate inflorescence.

Habitat:

Western aster may be found in mountain meadows. Variety intermedius may be found at lower elevations than variety occidentalis.

Range:

Aster occidentalis is found from British Columbia south through Washington and Oregon to California, and eastward to Idaho and Colorado.

Variety intermedius tends to be found in the eastern portion of the range of the species in eastern Washington and northern Idaho.

In the Columbia River gorge, variety intermedius may be found between the elevations of 200'-2000' from Bingen, WA east to

Biggs, OR..

Larger western mountain aster blooming on the cobbly shoreline of Pierce Island, Columbia Land Trust lands in the western Columbia River Gorge.........September 7, 2018.

One of the larger (and wider) stem leaves of Aster occidentalis var. intermedius as found at the mouth of the Deschutes River.........September 3, 2000.Note the narrow bracts tapering gradually to a fairly sharp point in the picture at right from the same location.

Paul Slichter