New Zealand’s woody indigenous eudicot flora comprises a variety of leaf shapes and features and occupies environments extending from subtropical to cold temperate climates. We used a dataset of over 300,000 occurrences of 557 indigenous woody eudicot species to investigate patterns and trends in the occurrence of six leaf features (leaf pubescence, leaf margin teeth, leaf size, leaf apex and base shape, and leaf length to width ratio) along critical climate gradients. Major climate variables examined included temperature, precipitation, moisture deficit and solar radiation. Our results reveal strong latitudinal gradients in toothed leaves and leaf area with both declining at higher latitudes. Leaf base and leaf apex angle are also aligned latitudinally, both declining in northern areas. In contrast, the occurrence of pubescent leaves and leaf length to width ratio are independent of other leaf features and latitudinal gradients. Larger leaves are positively associated with warmer climates while serrated margins are more common in warmer and wetter zones. The occurrence of pubescent leaves is greatest in seasonally dry environments with low annual precipitation. Long thin leaves (high length to width ratio) were more common in areas with a high rainfall to potential evapotranspiration ratio. Leaf apex angle is negatively correlated with temperature while leaf base angle distribution in relation to climate was highly variable. Overall, results confirm global patterns for leaf size and climate, highlighting the importance of small leaves limiting heat loss in cool climates. The positive correlation between leaf teeth and warmer climates has not been found elsewhere. High occurrence of pubescent leaves in low rainfall and highly moisture deficient environments in New Zealand suggests that the trait is associated with water retention in dry climates.

Dataset includes:

- Table S1: New Zealand species leaf morphological data derived from descriptions referenced in the dataset.

- Table S2: Geodetic coordinates of plot centroids in New Zealand with associated leaf trait variables, derived from species descriptions in Table S1 and species occurrences from https://doi.org/10.15468/bxxmis, https://doi.org/10.15468/ab3s5x and https://doi.org/10.15468/uzxpbn

- Table S3: Geodetic coordinates of plot centroids in New Zealand with associated climate variables derived from Leathwick, J. R., Morgan, F., Wilson, G. J., Rutlegde, D., McLeod, M., & Johnston, K. (2002). Land Environments of New Zealand: A technical guide. Ministry for the Environment, Auckland, New Zealand.