Centaurea debeauxii subsp. thuillieri

Forms of Centaurea nigra agg. with showy, pseudo-radiate inflorescences are frequently encountered in West Glamorgan in roadside verges and along open forest tracks. Identification of these forms has become difficult because of the current confusion surrounding Centaurea nigra and Centaurea debeauxii. Forms of Centaurea nigra (sensu stricto) with pseudo-radiate florets have been called Centaurea nigra ssp. rivularis and those of Centaurea nigra have been called Centaurea debeauxii ssp. thuillieri. More field data is required to resolve this issue in West Glamorgan and until that is possible it may be better to regard all these forms as part of Centaurea nigra agg.

See description of Centaurea nigra.