Thelypteris verecunda is a rare species of fern known by the common name Barrio Charcas maiden fern. It is endemic to Puerto Rico, where it is known from only three localities. It is a federally listed endangered species of the United States. This fern was first described in 1985. It was placed on the endangered species list in 1993. At that time it was known to exist at three locations in Quebradillas, Hatillo, and San Sebastián in Puerto Rico. Two of these localities have only one individual each. At Barrio Bayaney in Hatillo there are 20 plants.