In eastern Belgium, diploid and tetraploid knapweeds (Centaurea jacea L. s. l.) show a parapatric distribution with a contact zone. To compare the success of inter- and intra-cytotype crosses, and to ...

December’s Weed of the Month is not one, but three species of knapweed: brown knapweed (Centaurea jacea), meadow knapweed (C. x moncktonii), and diffuse knapweed (C. diffusa). All three species are ...

Two naturally coexisting grassland species - Centaurea jacea (often predominating) and Fragaria vesca (subordinate) were grown together in a pot experiment of factorial design, where competition and ...

IN Centaurea Jacea, the flower-heads of the same stem, as far as I have seen, are always of the same form, but different stems of the same locality often present astonishing difference in their flower ...