Syntenic nuclear genes and morphology reveal unusual new climbing bamboo species of <i>Melocalamus</i> in the Gaoligong Mountains

Abstract The Gaoligong Mountains at the border between China and Myanmar, a connection of global biodiversity hotspots in continental Southeast Asia, are full of a remarkable and unusual diversity of woody bamboos. Herein, by integrating morphological evidence with both plastome and three subgenome‐level syntenic nuclear gene datasets, we describe and illustrate two new endemic species of Melocalamus with climbing/scrambling habit: M. gaoligongshanensis sp. nov. and M. putaoensis sp. nov. from the Gaoligong Mountains. Morphological and molecular studies support the new species, while the phylogenetic reconstructions using different subgenome‐level syntenic nuclear gene datasets revealed incongruent phylogenetic topologies within Melocalamus , suggesting complex evolutionary patterns. By using both syntenic nuclear genes and plastomes with different analytical tools, our study provides novel methodological insights for elucidating the complex reticulate evolutionary history of Melocalamus . Moreover, as the occurrence of Melocalamus may be indicative to the ecosystem health of seasonal rain forests and monsoon evergreen broadleaved forests, our study suggests an alternative way to reassess the status of biodiversity in Gaoligong Mountains and lays the groundwork for further investigations of species diversity in this hotspot region.