The form and function of plants are immensely varied. But how constrained are traits when it comes to evolutionary viability and success? This massive study relies in part on GBIF-mediated data to examine plant trait variations at a global scale and draw a quantitative picture of functional diversity in 46,000 vascular plant species. Placing the plants into a six-dimensional trait matrix, the authors reveal how highly correlated and strongly constrained traits are, suggesting that a only small set of trait combinations are successful. Overall, the study presents a generalized backdrop for understanding plant biology and a global model for mapping the evolution of individual trait variations.