This paper deals with the occurrence of Juncus alpino-articulatus subsp. arthrophyllus (syn. J. fuscoater) in the Netherlands, especially in Twente, the eastern part of the province of Overijssel. This Juncus is very rare in the Netherlands. Formerly, it had been recorded from some localities in the so-called Fluviatile district, chiefly along the river Waal; in this region it is restricted nowadays to one locality in the Ooijpolder near Nijmegen. In recent years it has been discovered in three localities in Twente, and also in the southern part of the province of Limburg. A description is given of two localities in Twente. They represent two different types of habitat of this rush: in one, it occurs in the transition zone between Molinia caerulea vegetation and sedge marsh with pleurocarp mosses; in the other locality, it is found in a loam-pit. Two other localities, described by others, likewise show these two types of habitat, and the same is true in the Rhine valley in the south of Germany, according to PHILIPPI (1960, 1969).