Alfred Giard, On a fast-spreading weed (Matricaria discoidea D. C), in the Feuille des jeunes naturalistes, vol. 31-33, 1900-1903, p. 188 states: "The Catalogue of Vascular Plants of Ardennes (Charleville, 1900), a posthumous work by Albert Callay, tells us (p. 249) that M. discoidea was seen in June 1861 by Bouffray on the Canal des Ardennes dike near the Rilly Lock. At that time the plant was not reported by Reichenbach except around the village of Schoeneberg near Berlin. Callay guessed that the Ardennes location, where the plant had also not previously been seen, came from seeds mixed in cereal made for the Rilly mill." (in French)
