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Aim Elevation is an important factor that influences bioregionalisation in mountainous areas, but its effects are not well known. Taking the Sino‐Himalayan flora as a case, we aimed to test the effect of elevation on bioregionalisation and provide a regionalisation scheme of the Sino‐Himalayan flora. Location The Sino‐Himalaya (East Himalaya, the Hengduan Mountains and the Yunnan Plateau in China). Taxon Angiosperms. Methods We compiled distribution data and elevation ranges of angiosperms in the Sino‐Himalaya and adjacent areas and reconstructed a species‐level phylogenetic tree of 19,313 angiosperm species. The area was divided into 398 grid cells, each 1 × 1°. Nine datasets of different elevation ranges were then used to delineate the flora of the Sino‐Himalaya and adjacent areas using the phylogenetic dissimilarity approach. Results A comparison of nine regionalisation schemes of the Sino‐Himalayan flora based on different elevation range datasets revealed that more than half of grid cells were allocated to more than one subregion. Most of these grid cells were located in areas with a wide range of elevation and/or at the boundaries between subregions. After revising the subregion allocations of eight shifting grid cells, we generated a phylogeny‐ and elevation‐based regionalisation scheme of three regions, comprising eight subregions, for the Sino‐Himalayan flora. Main conclusions By integrating phylogenetic and elevational information, the Sino‐Himalaya can be divided into three floristic regions: the Yunnan Plateau region, the Hengduan Mountains region and the East Himalaya region. Our study provides novel insights into the regionalisation of the flora and highlights the importance of incorporating elevation data in the bioregionalisation of areas with a broad elevational range.

Biodiversity exchanges across the Malesian region, linking the distinct biotas of Asia and Australia, have long attracted the curiosity of biologists. Tetrastigma (Vitaceae) has a wide distribution in Asia through the Sunda archipelago to Australia and provides a good case to elucidate floristic exchange between Asia and Australia. Tetrastigma species have fleshy fruits that are consumed by birds, representing a lineage with a predictable dispersal across island chains. We herein estimate the divergence times and reconstruct the biogeographic history of Tetrastigma with intensive taxon sampling (96 of approximately 120 species; >80%) using 10 chloroplast loci. The biogeographic history of Tetrastigma was reconstructed with 4-area and 6-area divisions by delineating the Sunda region into one or three areas of endemism based on a phylogenetic bioregionalization analysis and the geological history of Malesia. The 4-area division shows that Tetrastigma originated in continental Asia and diverged from the recently segregated genus Pseudocayratia in the early Eocene (49.43 Ma). Dispersal from continental Asia might have started in the late Eocene but mainly occurred in the last 10 Myr. Continental Asia is indicated to be the most important source area while Sunda is the biggest sink, with 16 of the 27 dispersal events inferred from continental Asia to Sunda. Only seven dispersal events are inferred arriving in the Sahul plate and one reverse dispersal from Sahul back to Asia. The 6-area division suggests that the Philippines have been an active junction between Asia and Australia. The biogeographic history of Tetrastigma illustrates an asymmetric floristic exchange between Asia and Australia in this genus, which has been facilitated by the formation of terrestrial connections in the late Miocene and the expansion of wet tropical forests across Wallace's Line and beyond.