Distribution: Occurring on both sides of the Cascades crest in Washington; Yukon Territory to California, east across much of the U.S. and Canada to northeastern North America.
Habitat: Roadsides, fields, meadows, ditches, wastelots, and other disturbed, open areas; noxious.
Flowers: July-September
Origin: Introduced from the eastern Mediterranean region
Growth Duration: Annual, Perennial
Conservation Status: Not of concern
Pollination: Bees, flies, beetles, wasps
Diffusely branched annual or biennial 1-6 dm. tall.
Leaves small, more or less pinnatifid, the lower ones early deciduous, the reduced ones or the inflorescence mostly entire.
Heads numerous, narrow; involucre 8-10 mm. high, the middle and outer bracts coarsely comb-like and tipped with a slender spine 1.5-4 mm. long; flowers few, white or rose-purple, the marginal ones not enlarged; pappus wanting; receptacle densely bristly.
PNW Herbaria: Specimen records of Centaurea diffusa in the Consortium of Pacific Northwest Herbaria database
WA Flora Checklist: Centaurea diffusa checklist entry
OregonFlora: Centaurea diffusa information
E-Flora BC: Centaurea diffusa atlas page
CalPhotos: Centaurea diffusa photos