The leaf economics spectrum (LES) is a global set of patterns that describes correlations between functional traits (e.g. carbon assimilation rate, lifespan) that determine terrestrial resource fluxes. Several classes of models have been proposed to explain the LES, but none have been extensively tested against each other with fine-scale data. In a new study published in AoB PLANTS, Blonder et al. assemble a large set of genotypes of Arabidopsis thaliana that show variation in leaf functional traits. They show that no extant theory for the LES is supported, but that some leaf venation networks likely play a role in driving the pattern. Their study provides a roadmap for the measurements that could generate further insight into this fundamental ecological pattern.