In material of Cardamine pratensis from many localities in the Netherlands, the following somatic chromosome numbers were counted: 28, 30, 31, 32, 34, 36, 38, 39, 45, 46, 52, 53, 54, 56, 58, 59, 60, 62, 64, 64 à 66, 67, 68, 69, 70, 72, 73, 74, 75, 76, 78, (80), 84, and (118) 1). Many numbers were due to intra-individual deviation of the normal number. As main groups tetraploids with 28-32, octoploids with 56-64, and decaploids with 70-80 chromosomes could be distinguished; the normal numbers of the ploidy levels were 30, 60, and 74-76, respectively. Two subspecies could be distinguished on the basis of morphological, ecological, and cytological characters.