A program for polythetic numerical evaluation of phytosociological material is described. Using Sorensen's coefficient of floristic similarity it computes the homogeneity of subjectively chosen sets of releves, the affinity of each constituent releve to the set as well as the similarity between any pair of sets. It is also able to plot a dendrogram of the hierarchic system obtained by agglomerating individual releves into complex groupings. The program is suitable for processing phytosociological data arranged in any conventional table.