Morphological and molecular evidence suggests that Indosasa gigantea and Acidosasa glauca (Poaceae, Bambusoideae, Arundinarieae) are conspecific

<i>Indosasagigantea</i> is a bamboo with great economical value, but its generic designation has been controversial for a long time. This study aims to ascertain whether <i>I.gigantea</i> belongs to <i>Indosasa</i> or <i>Acidosasa</i>, based on morphological and molecular evidence from both plastome and single-copy nuclear orthologous genes. The results of phylogenetic analyses, based on plastid genomes and nuclear gene sequences, both strongly supported that <i>I.gigantea</i> is distantly related to other members of <i>Indosasa</i>, but clustered with <i>Acidosasaglauca</i>, the type species of <i>Acidosasa</i>. Further morphological studies demonstrated that <i>I.gigantea</i> is conspecific with <i>A.glauca</i>. Thus, <i>I.gigantea</i> was proposed as a synonym of <i>A.glauca</i>. Colour plates as well as a detailed description of this species are also provided.