To identify novel genes required for leaf development, we are screening the Arabidopsis Salk Unimutant collection. So far, we have identified more than 700 lines that exhibit a mutant leaf phenotype (Wilson-Sánchez et al., 2014). To allow indexing and comparison with other mutants, we described the mutant phenotypes using a custom leaf phenotype ontology. We found that the indexed mutation is present in the annotated locus in 76% of the lines studied. To enable comprehensive access to our data, we implemented a web application allowing researchers to query the results of our screen.