The two subspecies of Juncus alpino-articulatus Chaix ex Vill. found in the Netherlands, viz. subsp. atricapillus (Drejer ex Lange) Reichg. and subsp. arthrophyllus (Brenner) Reichg. are restricted there to two distinctly separated areas. The former subspecies occurs only near the coast, in the dunes, the latter far inland near the eastern border of the country. In 1962 the coastal subspecies was found on the border of a pond near Wijchen, i.e. within the area of the inland one. Recently an acceptable explanation of the curious occurrence was found. Near the said pond several species from other parts of the country were planted, a.o. Parnassia from the dunes, and it seems probable that seeds of the Juncus have come there in this way.