Capsella rubella, the pink shepherd's-purse, closely related to Arabidopsis thaliana in the Brassicaceae family, offers a valuable model for exploring the transition from self-incompatibility to self-compatibility in plant reproduction. Found primarily in the Mediterranean region, it diverged from its closest ancestor approximately 30,000 to 50,000 years ago, distinguishing itself from Capsella bursa-pastoris by its diploid genome.