Chromosome numbers of South African Umbelliferae (Apiaceae)

Chromosome numbers are reported for 12 species from nine genera of South African Umbelliferae, of which seven species and one genus (Itasina) are recorded for the first time. A detailed list of all published chromosome counts for southern African species is also presented, together with a review of the literature. The new data obtained are briefly discussed in the context of the taxonomy and relationships of local Umbelliferae. The counts agree with previous reports except that Annesorhiza appears to have 2n = 22, with or without one additional B-chromosome, and not 2n = 24 as reported in the literature. The number for Itasina (2n = 24) is of considerable interest and indicates that a detailed chromosome study of the South African genera Annesorhiza and Chamarea may yield valuable taxonomic information.