The area also includes several scarce plants, including lichens, and a rare damselfly, Coenagrion mercuriale.
The specific part of the scientific name, mercuriale, is because of the distinctive markings on the second segment of the abdomen that resembles the astrological symbol for the planet Mercury - ☿.
The site is of special interest for its population of the internationally rare southern damselfly (Coenagrion mercuriale), which breeds in this small valley near Afon Anghof, above Puncheston.