Symphyotrichum falcatum var. commutatum
Symphyotrichum falcatum var. falcatum

General:
Perennial herb from a fibrous-rooted, creeping rhizome; stems erect to ascending, branched and short-hairy above, 30-60 cm tall.

Leaves:
Basal leaves usually deciduous; stem leaves linear, unstalked, entire, usually stiff-hairy.

Flowers:
Heads with ray and disk flowers, several to many, solitary at the end of the branchlets, in racemes on the stem or branches; involucres 5-8 mm tall; involucral bracts graduated, linear-oblong to linear or the outer spoon-shaped with a whitish base, obtuse to abruptly sharp-pointed, the tips often loose, stiff-hairy and usually hairy on the backs; ray flowers 20-35, white, rarely pale pinkish or purplish-tinged, 5-10 mm long; disk flowers yellow.

Fruits:
Achenes several-nerved, hairy; pappus white.

Source:  The Illustrated Flora of British Columbia