Voorkomen en standplaats van Chrysosplenium alternifolium L. in de duinen van Voorne

Chrysosplenium alternifolium L., in the Netherlands a rare species of spring and rivulet habitats in pleistocene and older landscape of the eastern and south-eastern parts of the country, has recently been observed in a young holocene calcareous moist dune area on the island of Voorne in a hawthorn scrub at the border of an artificial rivulet. The author analyses the vegetation of the locality and considers it to be a fragmentary form of the Macrophorbieto-Alnetum cardaminetosum amarae. Since all other ”spring indicators” are absent, the possibility remains that the species has been introduced by man (wild gardening). However it must be stressed that in the previous century the species occurred at several comparable localities in the calcareous dunes near Haarlem where it disappeared as a consequence of drying up of the dunes by water extraction.