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 ...

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 ...

To evaluate the degree of introgressive hybridization in Finnish populations of Centaurea, starting with C. jacea and C. nigra, the author has, besides studying herbaria, analysed 32 populations, ...

Plant Systematics and Evolution, Vol. 298, No. 7 (August 2012), pp. 1349-1360 (12 pages) A population of Centaurea weldeniana was discovered recently near Wien (Vienna). The species is reported from ...

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