Welke soort rood zwenkgras (Festuca rubra s.l.) komt voor in de jonge kustduinen van Voorne en die van overig Nederland?

By common consent two taxa of Festuca rubra s.l. occur in sandy outer dunes along the N.W. European coasts. Festuca juncifolia St. Amans is considered to be a typical grass of Ammophiladunes. Festuca rubra subsp. arenaria (Osb.) Richt. could be found on almost fixed dunes. The only usable character mentioned in morphological descriptions, is formed by the sclerenchyma in the leafblades. In Festuca juncifolia the sclerenchyma must be present in a thick continuous layer. In Festuca rubra subsp. arenaria the sclerenchyma must consist of separate strands. In 1966 and 1967 58 samples of Festuca-plants, both vegetative shoots and culms, were collected on the outmost dune ridge on the island of Voorne (Netherlands). Almost all plants investigated appeared to possess separate sclerenchyma strands. From this it could be concluded that the Voorneplants belong to the taxon Festuca rubra subsp. arenaria. However, the authors prefer to follow KJELLQVIST (1964). According to this author the size of the sclerenchyma depends strongly on the environmental conditions, and the two traditional dune forms of Festuca rubra are identical.