Within Sedum acre L. s.l. a polyploid series occurs with the chromosome numbers 2n = 40, 2n= 60, 2n= 80, 2n= 100 and 2n= 120. The plants with 2n= 40 and 2n= 80 chromosomes have different areas. When cultivated under uniform conditions the cytotypes 2n= 40, 2n= 60 and 2n= 80 show differences in some morphological characters. It seems likely that these three cytotypes correspond with Sedum acre L. subsp. neglectum Ten., var. majus Masters, and subsp. acre, respectively.