Glebionis coronaria (L.) Tzvelev (syn.: Chrysanthemum coronarium L., Xanthophthalmum coronarium (L.) Schultz-Bip.) (Medit.) – A rather regular and increasing but always ephemeral alien. First recorded in 1903 on waste land in Sint-Kruis-Brugge. Subsequently also recorded in Oostende (1948), Mechelen (1955), Anseremme (1956), Beerse (1979) and Turnhout (1981), often on dumps. However, not formally recognized prior to 1997 (Verloove & Vandenberghe 1998). In the past decades frequently recorded in port areas or along canals, mostly associated with cereals (Antwerp, Ghent, Roeselare, Turnhout, etc.). Also sometimes seen in newly-sown road verges.
Most plants have whitish ligules with a yellow base and belong to var. discolor (d’Urv.) Turland (var. coronaria has concolorous ligules). The latter is somehow reminiscent of Glebionis segetum (see key for their separation).
Also, Glebionis coronaria (var. coronaria) is sometimes confused with Cota tinctoria in Belgian herbaria. Both are indeed superficially similar but easily distinguished: Glebionis has leaves with glabrous surfaces (villous to sericeous in Cota), receptacles scales are absent in Glebionis (receptacle paleate in Cota), etc.
Selected literature:
Turland N.J. (2004) (1647) Proposal to conserve the name Chrysanthemum coronarium (Compositae) with a conserved type. Taxon 53(4): 1072-1074.
Verloove F. & Vandenberghe C. (1998) Nieuwe en interessante voederadventieven voor de Belgische flora, hoofdzakelijk in 1997. Dumortiera 72: 18-36. [available online at: http://alienplantsbelgium.be/sites/alienplantsbelgium.be/files/dum72p18.pdf]