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Aim Early in their evolution, angiosperms evolved a diversity of leaf form far greater than that of any other group of land plants. Some of this diversity evolved in response to varying climate. Our aim is to test the global relationship between leaf form in woody dicot angiosperms and the climate in which they live. Location We have compiled a data set describing leaf form (using 31 standardized categorical characters) from 378 natural or naturalized vegetation sites from around the world. Our data include sites from all continents except Antarctica and encompass biomes from tropical to taiga, over a range of elevations from 0.5 m to over 3000 m. Methods We chose the Climate Leaf Analysis Multivariate Program sampling, scoring and analytical protocols to test the relationships between climate and leaf form, which is based on canonical correspondence analysis. Cluster analysis evaluates the role of historical factors in shaping the patterns, and pairwise Pearson correlations examine the relationships among leaf characters. Results Woody dicot leaf characters form a physiognomic spectrum that reflects local climate conditions. On a global scale, correlations between leaf form and climate are consistent, irrespective of climate regime, vegetation type or biogeographic history. Relationships with temperature variables are maintained even when leaf margin characters, regarded as being particularly well correlated with mean annual temperature, are removed. Main conclusions In natural woody dicot vegetation an integrated spectrum of leaf form has developed across multiple leaf character states and species. This spectrum appears more strongly influenced by prevailing climate than biogeographic history. The covariation of leaf traits across species suggests strong integration of leaf form. New methods of exploring structure in multidimensional physiognomic space enable better application of leaf form to palaeoclimate reconstruction.

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Summary Modern tropical rainforests have the highest biodiversity of terrestrial biomes and are restricted to three low‐latitude areas. However, the actual timeframe during which tropical rainforests began to appear on a global scale has been intensely disputed. Here, we used the moonseed family (Menispermaceae), an important physiognomic and structural component of tropical rainforests on a worldwide basis, to obtain new insights into the diversification of this biome. We integrated phylogenetic, biogeographic and molecular dating methods to analyse temporal and spatial patterns of global diversification in Menispermaceae. Importantly, a burst of moonseed diversification occurred in a narrow window of time, which coincides with the Cretaceous–Paleogene (K–Pg) boundary. Our data also suggest multiple independent migrations from a putative ancestral area of Indo‐Malay into other tropical regions. Our data for Menispermaceae suggest that modern tropical rainforests may have appeared almost synchronously throughout the three major tropical land areas close to, or immediately following, the K–Pg mass extinction.

The Menispermaceae, a largely tropical family of dioecious and predominantly climbing plants, have been the subject of various molecular studies that confirmed its monophyly and the para‐ and polyphyly of most of the currently recognized tribes. The newly recognized assemblages have been variously named informally in different studies. Here we present a comprehensive phylogenetic hypothesis of the Menispermaceae based on the analyses of three molecular markers (matK, trnL‐F, ndhF) and 41 morphological characters for the most extensive taxonomic and geographic sampling of the family as compared to earlier studies. Phylogenetic relationships were inferred using maximum parsimony, maximum likelihood, and Bayesian approaches. Our results of the combined molecular and total‐evidence datasets corroborate earlier findings, with an improved support for major clade contents. A new tribal classification of the Menispermaceae is proposed, in which nine clades are grouped within the subfamilies Chasmantheroideae and Menispermoideae, forming themselves two well‐supported clades. Within the Chasmantheroideae, the two clades recovered are here recognized as tribes Burasaieae and Coscinieae; within the Menispermoideae the seven identified clades are recognized as tribes Anomospermeae, Cissampelideae, Limacieae, Menispermeae, Pachygoneae, Spirospermeae, and Tiliacoreae. Of these, Spirospermeae is newly described, while the names, if not the circumscriptions, of the remaining tribes are adopted from earlier treatments. The subfamilies and most tribes here identified are further diagnosed by unique combinations of morphological characters. A few genera not sampled for the molecular analysis are provisionally assigned to the recognized tribes based on their floral, fruit, endocarp, and seed features.

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