
Leaf shape varies extensively across the plant kingdom and this variation is probably adaptive. Ferris et al. use next-generation sequencing to examine the genetic basis of leaf shape evolution in three edaphic specialists in the Mimulus guttatus species complex: M. laciniatus, M. nudatus and serpentine M. guttatus. Typical M. guttatus has rounded entire leaves and occurs in moist habitats, whereas the other taxa have either lobed or narrow leaves and occur in dry, rocky habitats. The results show that the genetic architecture of lobed and narrow leaf shape is highly similar in these three species and that shared genetic regions contain several genes involved in leaf shape evolution in other species.