Symphyotrichum hallii

Symphyotrichum hallii (formerly Aster hallii) is a species of flowering plant in the family Asteraceae endemic to western Oregon and Washington states. Commonly known as Hall's aster, it is a perennial, herbaceous plant with a long rhizome that creates colonies of itself. It grows about 30-60 cm tall, and has white (sometimes pale violet) rays that open July–August.

Most occurrences of the species have been found at elevations of 0–500 m in open areas in the Puget Sound region and Willamette Valley, with outliers in Columbia Gorge and central Washington. It is conservationally Imperiled (S2) in Washington state.