Centaurea jaceaL.

Brown Knapweed

WFO wfo-0000095537 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h

Centaurea jacea, photographed by Nico
fig. a Nico, CC0 1.0 / 2022-06-11 / obs. 205150642
Centaurea jacea, photographed by Yann Kemper
fig. b Yann Kemper, CC0 1.0 / obs. 203298573
Centaurea jacea, photographed by Марина Садыкова
fig. c Марина Садыкова, CC BY 4.0 / obs. 205691529
Centaurea jacea, photographed by ahabo
fig. d ahabo, CC BY 4.0 / obs. 203281643
Centaurea jacea, photographed by olrett
fig. e olrett, CC BY 4.0 / obs. 205127011
Centaurea jacea, photographed by Марина Садыкова
fig. f Марина Садыкова, CC BY 4.0 / obs. 203262632
Centaurea jacea, photographed by Jochen Essig
fig. g Jochen Essig, CC BY 4.0 / obs. 202740854
Centaurea jacea, photographed by Силаева Татьяна Борисовна
fig. h Силаева Татьяна Борисовна, CC0 1.0 / obs. 203569724

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

Confused withby our own model

These are not lookalikes we guessed at. Each one is a species our identification model genuinely mistook for this plant, and how many times. The error rate is published.

Flowering n = 3,501 observations

Peak flowering in Jul, from 3,501 community-annotated observations worldwide. This is a global aggregate, not a forecast for your garden: the same species flowers on different dates in different hemispheres, and citizen-science records cluster near cities, at weekends, and in spring. Where a species has fewer than 30 annotated records we do not draw this chart at all.

Also published as 79 synonyms

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

  • Behen jacea (L.) Hill
  • Calcitrapa jacea (L.) Peterm.
  • Centaurea alba Suter
  • Centaurea amara L.
  • Centaurea amara subsp. amara
  • Centaurea amara subsp. angustifolia Gremli
  • Centaurea amara subsp. timbalii (Martrin-Donos) Braun-Blanq. & al.
  • Centaurea amara subsp. weldeniana (Rchb.) Kušan
  • Centaurea amara var. amara
  • Centaurea amara var. approximata Rouy
  • Centaurea amara var. mairei Arènes
  • Centaurea angustifolia Schrank
  • Centaurea approximata (Rouy) Rouy
  • Centaurea bracteata Scop.
  • Centaurea commutata (Koch) Stankov
  • Centaurea consimilis Boreau
  • Centaurea croatica (Hayek) Soest
  • Centaurea decumbens Dubois ex Pers.
  • Centaurea dracunculifolia Dufour
  • Centaurea duboisii Boreau
  • Centaurea forojuliensis Poldini
  • Centaurea gaudinii Boiss. & Reut.
  • Centaurea gracilior Reut. ex Nyman
  • Centaurea hastata Gugler

and 55 more.

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.

We publish what we can source and we say so when we cannot. This page has no care advice, no toxicity claim and no native range, because we do not yet have those from a source we can cite.