Arthrostylidiinae are one of the three subtribes of Neotropical woody bamboos and comprise 13 genera and over 160 described species. Recent phylogenetic analyses have demonstrated both the non-monophyly of Aulonemia Goudot and the sister relationship of Aulonemia ulei (Hack.) McClure to the monotypic Glaziophyton Franch., with which it forms a clade sister to the reminder of the subtribe. Based on these data and on morphological and anatomical characters, we present herein the new monotypic genus Cambajuva, as well as a new combination, to accommodate A. ulei. Morphological and anatomical descriptions are also provided, as well as a comparison with putatively related genera of the subtribe.