Aristida chaseae Hitchc.

Aristida chaseae Hitchc.. Aristida chaseae is a rare species of grass known by the common name Chase's threeawn. It is endemic to Puerto Rico, where it is known from two locations in the Cabo Rojo National Wildlife Refuge and the Sierra Bermeja. It is a federally listed endangered species of the United States. It cannot compete with introduced species of grasses, such as Brachiaria subquadripara, which are invading its habitat.