Avena occidentalis, a hitherto overlooked species of oats

Avena occidentalis Dur., hitherto known from only one specimen, was found to occur in three islands of the Canaries and in one locality in Portugal. The speculation that this might indicate a greater past distribution is strengthened by a few examples of species with a similar present distribution in the Canaries and with known fossil records from Europe. Some morphological character states of A. occidentalis are described and they are compared with character states from homologous organs in morphologically similar species. The possible importance that A. occidentalis might have for the understanding of the cytogenetical relationship between the Avena species is stressed, and the possible value of this species to agriculture is mentioned.