Distribution: Occurring east of the Cascades crest in central and south-central Washington; central Washington to California, where native east to Idaho, Nevada, and Arizona.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed, open places at low to middle elevations.
Flowers: July-Sept.
Origin: Introduced from California
Growth Duration: Annual
Conservation Status: Not of concern
Pollination: Bees, flies, beetles, wasps
Coarse annual 1-10 cm. tall, somewhat hairy.
Leaves alternate, numerous, pungent, rigid, the lower 2-6 cm.long, pinnatifid, the upper smaller and linear.
Heads several, hemispheric; involucre 3-5 mm. high, with firm, spine-tipped bracts each clasping the outer half of a ray achene, closely subtended by linear, spine-tipped leaves; rays 15-35, pale yellow, 4-7 mm. long, 2-toothed; disk flowers yellow, sterile; receptacle convex, chaffy throughout; pappus none.
Achenes
Publication: Man. Bot. San Francisco. 196. 1894.
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ssp. pungens – common spikeweed, western spikeweed
PNW Herbaria: Specimen records of Centromadia pungens in the Consortium of Pacific Northwest Herbaria database.
WA Flora Checklist: Centromadia pungens checklist entry.
OregonFlora: Centromadia pungens information.
E-Flora BC: Centromadia pungens atlas page.
CalPhotos: Centromadia pungens photos.
USDA Plants: Centromadia pungens information.
