Calendula officinalis L. (Hort.?) – A very common ornamental species, often found as an escape or throw-out but probably always ephemeral. Apparently first collected in 1858 near the cathedral of Gent. Subsequently recorded in numerous, very widely scattered locations. Calendula officinalis is usually found in or near gardens, on dumps or waste land, along road verges, etc. In 2007 also found among birdseed aliens in the city of Ghent.
The plants that are currently found in cultivation are probably of unknown, artificial origin.
Lude A. (1993) Untersuchungen über die heterokarpen Achänen bei der Gartenringelblume Calendula officinalis L. (Asteraceae). Jahresh. Ges. Naturk. Württemberg 148: 111-126.