Witte engbloem (Vincetoxicum hirundinaria Med.) in het rivierengebied van Nederland

It was doubtful whether Vincetoxicum hirundinaria Med. was still present in the Dutch riverine area. It seems to have disappeared from its original locality near Millingen, but is present already for several years at a new, more western locality. A garden experiment showed that the plants are fully fertile. Nevertheless the population seems to be declining.