In Arabidopsis thaliana, the GLABRA 1 (GL1) gene encodes a R2R3-MYB transcription factor that regulates epidermal genes necessary to promote trichome initiation. To determine whether the GL1 gene is also involved in the stomatal patterning of rosette leaves, the epidermal cell pattern of a glabrous mutant (gl1-1) was compared to that of the wild type Columbia ecotype. The gl1-1 mutant was found to have lower stomatal densities and greater distances between stomata as compared to the Columbia ecotype. These findings suggest that stomatal patterning and trichome developmental processes share genetic components to specify cell fate and identity.