Although they are relative latecomers on the evolutionary scene, having emerged only 135?170 million years ago, angiosperms—or flowering plants—are the most diverse and species-rich group of seed-producing land plants, comprising more than 15,000 genera and over 350,000 species. Not only are they a model group for studying the patterns and processes of evolutionary diversification, they also play major roles in our economy, diet, and courtship rituals, producing our fruits, legumes, and gr...