An Overlooked New Endemic Species of Rhipidocladum (Poaceae: Bambusoideae: Bambuseae: Arthrostylidiinae) from Mexico

Rhipidocladum is the fourth most speciose genus in the bamboo subtribe Arthrostylidiinae. The species in this genus have a wide geographical distribution from North America (Mexico) to South America (Argentina). In Mexico, there are five Rhipidocladum species, two of which are endemic. During a recent review of herbaria, we found some specimens of Rhipidocladum from Guerrero, Jalisco, and Nayarit that do not fit morphologically with any of the five Rhipidocladum species presently known in Mexico nor any other species in the genus. Here we describe and illustrate Rhipidocladum barbinode, a new species endemic to Mexico. We additionally provide an updated morphological key to the Rhipidocladum species of Mexico.