Perennial herb from a stout rhizome; stems erect, solitary, branched, glabrous to sparsely hairy, dotted with glands, 0.4-1.5 m tall.
Basal leaves lacking; stem leaves alternate, 10-20 cm long, 4-8 cm wide, unstalked or short-stalked, pinnately cut, the axis of the inflorescence evidently winged, the ultimate segments again pinnately cut or deeply lobed and toothed.
Heads disciform, numerous, terminal on the branches in a short, flat- to round-topped inflorescence; involucres 2-3 mm tall; involucral bracts lanceolate, in 2-3 series, keeled, firm except for the papery margin, hairy at the base; ray flowers lacking; marginal flowers glandular, 3-lobed; disk flowers yellow, 5-toothed into rounded lobes, sparsely glandular.
Achenes squared off at top, 1 mm long, 5-angled, glandular-dotted; pappus a minute, narrow-toothed crown.
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(1), CWH(6), ESSF(1), IDF(3), SBS(1)|
Source: Klinkenberg 2013
Synonyms and Alternate Names:
Tanacetum boreale Fisch. ex DC.
Tanacetum vulgare var. crispum DC.
1. Heads disciform, numerous, usually 20-200.......................T. vulgare
1. Heads with ray and disk flowers, few to many, usually less than 20
2. Rays flowers white; leaves once or twice pinnately divided, the relatively broad segments often overlapping.......................T. parthenium
2. Rays flowers yellow; leaves twice to three times pinnately divided, the segments not at all overlapping........................T. bipinnatum
Source: Illustrated Flora of British Columbia
This species has become a common invader in southern British Columbia, often forming thick stands along roadsides and railway track verges. It is listed as one of the top fourteen species of concern by the Coastal Invasive Plant Committee, for more information visit their web site.