In 1978 and 1979 Polystichum lonchitis (L.) Roth and Asplenium viride Huds. were found for the first time in the Netherlands. Both were growing on ditch-sides in the forest ‘Kuinderbos’ at 3-3,5 m below sealevel on calcareous sand. The former occurred in a plantation of Fraxinus excelsior, the latter in a plantation of Picea sitchensis. The nearest localities are in West-Germany, but it is possible that both were transported by western winds from Great Britain.