Chusquea gibcooperi (Poaceae: Bambusoideae: Bambuseae: Chusqueinae), a new species endemic to Mexico

The Perote-Orizaba region in Veracruz and the Alto Soconusco in Chiapas encompass the highest diversity of Chusquea species in Mexico, followed by the Sierra de Juarez in Oaxaca. These three regions have a total of 15 known Chusquea species. With the description here of Chusquea gibcooperi the number of described Chusquea species in Mexico will increase to 21. Chusquea gibcooperi is here described as a new species endemic to Mexico, inhabiting neotropical cloud forest and the ecotone with pine forest in the Perote-Orizaba area, Veracruz, and the Sierra Madre Oriental in Hidalgo and Puebla. Chusquea gibcooperi is similar to C. enigmatica and C. glauca, but differs from the former in having taller and wider culms and longer and wider foliage leaf blades. Chusquea glauca has maculate culms, a ring of cilia at the base of the culm leaf, infravaginal branching, and abaxially pubescent foliage leaf blades. The culms of Chusquea gibcooperi are uniform in color (i.e., not maculate), the culm leaves lack the basal ring of cilia, branching is both intravaginal and extravaginal, and the foliage leaf blades are abaxially glabrous.