Apera interrupta (L.) Beauv. (Stijve windhalm), een dwaalgast burgert in

Apera interrupta (L.) Beauv. was found in 1984 in the province of Zeeland (Rammegors) in a rather natural habitat on sandy soil. In 1986 the species was also discovered in the province of Limburg (in Kerkrade). Until then A. interrupta was considered to be an adventitious species only. From a study of herbarium specimens it appeared that the species had been recorded previously in 1943 and 1958 in the province of Zuid-Holland (Leiden). Recently it turned out to be still present at both localities (a railway-embankment and a former railway). As the number of records has increased significantly – since 1943 the species has been recorded in 10 hour-squares among which nine new localities near Amsterdam in 1988 – it is argued that the Netherlands, just like Belgium, Luxembourg and Germany, are in fact part of the large discontinuous area of the species. The authors therefore suggest that it is more appropriate to consider A. interrupta as a new, but still local and rare denizen which is indigenous to sandy, open, often freshly disturbed habitats such as waste grounds, building sites and railway-embankments.