Abstract
Karyotypes of Hexastylis arifolia, H. lewisii, H. virginica, Asarum canadense, and A. caudatum were compared. Karyotypic differences were not apparent among species of the subgeneric groups of Hexastylis. Species of Hexastylis possess 10 pairs of chromosomes with median centromeres and 3 pairs with submedian centromeres, differing from the two species of Asarum, which possess 11 and 2 chromosome pairs with median and submedian centromeres, respectively.