Vicia tenuifolia Roth has established itself in the Netherlands since several years. The species is compared with Vicia cracca L., of which it differs by a number of well-known morphological characters, and moreover by the fact that its flowering period is very short and rather early, beginning about the middle of May and lasting about 2 weeks; it then flowers abundantly and forms compact masses at the end of its flowering-time and at fruiting time.