Two species of Petunia, P. linearis and P. calycina were grown from seed collected in the wild. Their chromosome number (2n = 18) and karotype morphology have been studied. Both species seem to be related to P. parviflora. which found support in peroxidase isozyme data. The three 2n = 18 species differ considerably from the Petunia species with 2n = 14 chromosomes.