Karyotype analyses were made using root tip mitosis in 21 species of South Indian Apiaceae. First record of chromosome numbers have been made in Hydro-cotyle conferta (2n=18), H. rotundifolio (2n=18), Pimpinnella pulneyensis (2n=18), P. candolleana (2n=18), Heracleum rigens (2n=40), H. ceylanicum (2n=44), H. sprengelianum (2n=14), H. courtallense (2n=40) H. hookerianum (2n=46), H. aquilegifolium (2n=46), H. candolleanum (2n=40) and H. pedatum (2n=46). The most commonly occurring somatic chromosome number is 2n=18 and 2n=22. It is evident from the present investigation and those data available from earlier studies in this family that aneuploidy and euploidy together with karyotypic asym-metry of chromosomes play important role in the origin and evolution of the species studied.