Varens in de Lickebaert

Since the late 1980s considerable parts of the rural area between Maassluis and Vlaardingen (the Lickebaert) have been afforested. Ferns settled relatively recently in the new groves, successively Dryopteris dilatata (very common in the Netherlands), D. filix-mas (common, rare in our floral district ‘Hafdistrict’ (H), the floral district that roughly comprises the soils below sea level), Asplenium scolopendrium (very rare outside the Urban Districts (Ur)), D. carthusiana (very common), and Athyrium filix-femina (common). In Winter 2014–2015, Polypodium vulgare (very rare in H) and 14 and 5 specimens of, respectively, Polystichum setiferum and P. aculeatum were found. Both Polystichum species are very rare in the IJsselmeerpolders (Y), Urban and South Limburg (Z) Districts, but have also been recorded elsewhere. Dryopteris affinis subsp. affinis and D. a. subsp. borreri (both very rare) followed in 2015. Polypodium interjectum (rare outside the Rhenodunal District (R)) has only been found in the old decoy Aalkeetbuiten. Ophioglossum vulgatum (very rare outside the Dune Districts) is numerous on the north slope of the age-old Maassluisse Dijk. A c. 70 m2 patch of Pteridium aquilinum (very rare in H) is present on a dam of the Rietputten. Asplenium ruta-muraria (locally fairly common in Urban districts) grows on walls of the pumping-station at the end of the Boonervliet. Azolla filiculoides (locally common in H) occurs in several ditches in the area.