Biennial or winter annual herb from a fibrous root; stems erect, branched above, solitary, glabrous, exuding milky juice when broken, 0.3-1.5 m tall.
Basal leaves lacking; stem leaves alternate, prickly on the underside midrib, finely so on the margins, pinnately lobed or sometimes lobeless, twisted at the base to lie in a vertical plane, arrow-shaped, clasping, mostly 5-30 cm long, 1-10 cm wide.
Heads with strap-shaped flowers, numerous in a rounded inflorescence; involucres 10-16 mm tall; involucral bracts linear-lanceolate, irregularly graduated in 4 series; ray flowers yellow, often drying to blue, 13-47.
Achenes prominently nerved, grey or yellowish, 6-7 mm long with the slender beak 1-2 times as long as the body, compressed; pappus whitish.
If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.
Illustration Source: The Illustrated Flora of British Columbia
||Value / Class
Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
of field plots
species was recorded in:
BEC Zone Class
All BEC Zones (# of stations/zone) species was recorded in
|BG(11), CWH(2), ICH(8), IDF(7), PP(7), SBS(1)|
Source: Klinkenberg 2013
Synonyms and Alternate Names: