E-Flora BC: Electronic Atlas of the Flora of British Columbia

Centaurea stoebe subsp. micranthos L. (Gugler) Hayek
spotted knapweed
Asteraceae (Aster family)

Introduction to Vascular Plants

© Jim Riley  Email the photographer   (Photo ID #456)

E-Flora BC Static Map
Distribution of Centaurea stoebe ssp. micranthos
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Species Information

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Biennial or sometimes perennial herb from a taproot; stems erect, ridged, laxly branched, 0.2-1.8 m tall.
Basal leaves pinnately cut, linear, stalked; stem leaves becoming reduced and unstalked above.
Heads discoid, few to several, in a corymb-like arrangement at the ends of ascending branches; involucres 9-13 mm tall, 6-8 mm wide; involucral bracts oblong, grooved, membranous, the middle and outer ones bearing a relatively narrow, darkened comb-like tip; disk flowers purple to pinkish-purple, rarely white, the sterile marginal ones 18-20 mm long, enlarged at the tips with 5 narrow lobes, the central perfect ones 12-16 mm long.
Achenes dark grey to black, 2.5-3.5 mm long; pappus white, 0.5-2 mm long, rarely lacking.
This species is sometimes difficult to separate from the closely related C. paniculata. The latter, however, has much stiffer, divergent branches that are often again branched with narrower heads.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Dry roadsides and fields in the steppe and montane zones; frequent in S BC east of the Coast-Cascade Mountains; introduced from Eurasia.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Centaurea stoebe ssp. micranthos

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres) 296 750 1340
Slope Gradient (%) 0 38 78
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
40 187 346
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
0 2 5
Modal Nutrient Regime
Number of field plots
 species was recorded in:
Modal BEC Zone Class
All BEC Zones (# of stations/zone) species was recorded in: BG(5), ICH(28), IDF(18), PP(15)


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

Synonyms and Alternate Names

Acosta maculosa auct. non (Lam.) Holub
Centaurea biebersteinii D.C.
Centaurea maculosa auct. non Lam.

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References