Centaurea macrocepala Willd. (syn.: Grossheimia macrocephala (Willd.) Sosn. & Takht.) (Caucasus) – A very rare and ephemeral alien. Recorded in a garden in Auderghem (Brussels) in 1988, possibly from discarded bird seed. In 2012 also observed by a track in Maisières near Mons (most likely from garden waste).
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