Studies at the nucleotide level on the nuclear flower development gene cycloidea (cyc) in seven Antirrhinum, two Misopates, one Linaria, one Cymbalaria, and one Digitalis species revealed that cyc is a member of a gene family composed of at least five apparently functional genes. The estimated ages of the duplication events that created this gene family are from 7.5 Myr to more than 75 Myr. We also report the first estimates of DNA sequence diversity for species of Antirrhinum and Misopates. Low between-species variability suggests that this group of species may have diverged recently.