Centaurea jacea L., 1753

🇬🇧 Brown Knapweed

🇫🇷 Ambrette, Centaurée jacée, Tête de moineau

Taxonomy

Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Superasterids
Clade: Asterids
Clade: Campanulids
Order: Asterales
Family: Asteraceae
Subfamily: Carduoideae
Tribe: Cardueae
Subtribe: Centaureinae
Genus: Centaurea
Species: Centaurea jacea

Subspecies

Centaurea jacea subsp. jacea

Centaurea jacea subsp. timbalii

Presence

Present.

Conservation status

Red List (Metropolitan France): LC Least Concern

Notes

Possible confusion with C. decipiens Thuill., 1799 or C. nigra L., 1753, whose flowers have phyllaries with a ciliate appendage, while those of C. jacea have phyllaries with an entire or lacinate appendage.

Some plants have fimbriate appendages, with an appearance intermediate between C. jacea and C. decipiens. This could be due to introgression from C. decipiens (Tison & de Foucault, 2014), which is itself likely a stabilized hybrid of C. jacea × C. nigra. This kind of specimen is quite common in south-west France, especially in mixed populations where “pure” C. jacea specimens are rarer.

Their appearance is somewhat similar to the hybrid C. × gerstlaueri Erdner, 1905 present in North America and considered an invasive species in several places, and native to France and neighboring countries; however, its presence in France is not usually recognized and the treatment of these specimens remains problematic. This hybrid could be the one from which C. decipiens originates.

The following infraspecific taxa are accepted:

C. jacea subsp. angustifolia (DC.) Gremli, 1874, Q;
C. jacea subsp. banatica Hayek, 1918;
C. jacea subsp. dracunculifolia (Dufour) A.Bolòs, 1950, P (hom. syn. C. dracunculifolia Dufour, 1831);
C. jacea subsp. forojulensis (Poldini) Greuter, 2003;
C. jacea subsp. gaudinii (Boiss. & Reut.) Gremli, 1874, Q;
C. jacea subsp. haynaldii (Hayek) Hayek, 1918;
C. jacea subsp. jacea L., 1753, P;
C. jacea subsp. julica (Hayek) Greuter, 2003;
C. jacea subsp. substituta (Czerep.) Mikheev, 1999;
C. jacea subsp. timbalii (Martrin-Donos) Braun-Blanq., 1952, P;
C. jacea subsp. vinyalsii (Sennen) O.Bolòs, Nuet & Panareda, 1986;
C. jacea subsp. weldeniana (Rchb.) Greuter, 2003.

Photographs

img/centaurea-jacea.webp — *Centaurea jacea*

img/centaurea-jacea-2.webp — *Centaurea jacea*

img/centaurea-jacea-3.webp — *Centaurea jacea*

img/centaurea-jacea-4.webp — *Centaurea jacea* - Flower bud

Sources

Tison, J.M., & de Foucault, B. (2014). Flora Gallica : Flore de France (p. 413). Biotope.