Dieteria canescens var. canescens

General:
Biennial or short-lived perennial herb from a taproot; stems erect, several, branched, grey-hairy, 0.1-1.0 m tall.

Leaves:
Basal leaves simple, toothed, the teeth and the leaf tips spine-tipped, linear to more egg-shaped, 1.5-10 cm long, 3-15 mm wide, often deciduous; stem leaves similar, reduced, alternate.

Flowers:
Heads with ray and disk flowers, usually numerous in a rounded inflorescence; involucres 6-10 mm tall; involucral bracts linear to lance-linear or lance-oblong, grey-hairy or glandular or both, graduated, overlapping, with short, green, crimped tips; ray flowers bright purple, 8-25, 5-12 mm long; disk flowers yellow.

Fruits:
Achenes 2- to 4-nerved, somewhat compressed, finely silky-hairy, 2.5-4 mm long; pappus of soft white bristles.

Source:  The Illustrated Flora of British Columbia

Synonyms and Alternate Names:
Machaeranthera canescens (Pursh) A. Gray