Pseudechinolaena polystachya (Kunth) Stapf, belonging to the grass family, is widely distributed in America, Aferica and Asia. This species is characterized by its upper glume of spikelet densively covered with long hooked-hair in fruiting stage. In a recent plant survery, we found a wild naturalized population of Pseudechinolaena polystachya in Central Taiwan. A detailed description with color photographs, linedrawing and habitat information is provided in this paper.