Oenothera paradoxa (Onagraceae) in Belgium

Oenothera paradoxa was described in 1968 from the former German Democratic Republic (East Germany). For quite a long time it was only known from scattered localities. In Belgium it was poorly known and only recorded from a single locality; for this reason O. paradoxa was not included in a recently published identification key for Oenothera in Belgium. However, in the past years this species was observed in several new localities, in Belgium as well as in other parts of Europe. It is in fact a very characteristic and easily recognized species. In this short note distinguishing features of O. paradoxa are discussed and the species is copiously illustrated.