A new species of Chusquea subg. Swallenochloa (Poaceae: Bambusoideae) from the Peruvian upper montane forest

A new woody bamboo from Peru, Chusquea robinfosteri, is described here based on a combination of morphological and anatomical characters. Within Chusquea subg. Swallenochloa, C. robinfosteri and C. depauperata are similar in having awnless falcate spikelets, foliage leaf blades with the abaxial epidermis exhibiting abundant single and branched papillae, a simple midrib, and mesophyll comprising rosette cells and lacking fusoid cavities. The two species are distinguished mainly by the presence or absence of glumes and the shape of the leaf sheath summit extension. While C. robinfosteri usually has both glumes I and II developed and a long acuminate foliage leaf sheath summit extension, C. depauperata usually lacks glumes I and II and has a truncate foliage leaf sheath summit extension. The description of the new species is accompanied by detailed photographs captured under a stereomicroscope, images of the foliage leaf blade anatomy and micromorphology, a morphologically comparative table, diagnostic key, and map indicating the type locality. Likewise, detailed images of C. depauperata are provided.