Aristida portoricensis

Aristida portoricensis is a rare species of grass known by the common name pelos del diablo. It is endemic to Puerto Rico, where it is known from two locations, one in a residential area of Mayagüez and one in the Sierra Bermeja. Two other known sites have been extirpated by development of the habitat. It is a federally listed endangered species of the United States.
This is a perennial grass producing a tuft of stems up to 30 to 50 centimeters tall. The inflorescence is a narrow panicle a few centimeters in length. Its habitat includes subtropical wet forests and grassland on soils of clay and serpentine origin. Development of the Sierra Bermeja is a potential threat for the grass and many other endemic plant species. Vandalism of the few remaining plants is also a potential threat.