Scheuchzeria palustris L. in 1974 in de oostelijke Belgische Kempen

The authors report the discovery of Scheuchzeria palustris L. in the eastern part of the Belgian Kempen in the summer of 1974. This find is of importance a.o. from the viewpoint of plantgeography, since Scheuchzeria had not been found in Belgium after 1946, and therefore was considered extinct there. The species had never been reported earlier from the region where it was found in 1974 (fig. 1). In August 1974 14 plants in fruit were counted in a bog situated on a plateau consisting of fluvial sand and gravel deposits of pleistocene origin, about 90 m above sea level, in the municipality of Maasmechelen. The plants grew in a depression between a Sphagnum island and the gradually rising margin of the fen, together with Sphagnum cuspidatum, Juncus bulbosus, and Eriophorum angustifolium (fig. 2). According to the French – Swiss School of vegetation classification, the fytocoenosis of which Scheuchzeria palustris forms a part, belongs to the Rhynchosporion albae W. Koch 1926; class Scheuchzerietea Den Held, Barkman & Westhoff 1969. Scheuchzeria was found in an ombrotrofic bog the water level of which can vary a few tens of centimeters. Measurements of the pH at two different times gave values of 4,1 and 4,2. It is gratifying in the light of the rapidly decreasing number of stations of Scheuchzeria palustris in the Nortwestern European lowland that the newly discovered locality in Belgium is not under an immediate threat, so that its continued existence seems guaranteed for some time to come.