''Amauropelta inabonensis'',

synonym A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...

''Thelypteris inabonensis'', is a rare species of

fern The ferns (Polypodiopsida or Polypodiophyta) are a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. They differ from mosses by being vascular, i.e., having specialized tissue ...

known by the common name cordillera maiden fern.''Thelypteris inabonensis''.
USDA Plants Profile. It is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

Puerto Rico ; abbreviated PR), officially the Commonwealth of Puerto Rico, is a Government of Puerto Rico, self-governing Caribbean Geography of Puerto Rico, archipelago and island organized as an Territories of the United States, unincorporated territo ...

, where it is known from only two localities: at the headwaters of

Río Inabón Río Inabón is one of the List of rivers of Ponce, 14 rivers in the municipality of Ponce, Puerto Rico. With a length of some , it is Ponce's second longest river after Río Jacaguas. It is fed by the Río Anón, Río Guayo (which itself is f ...

and at the

Toro Negro State Forest Toro Negro State Forest (Spanish: ''Bosque Estatal de Toro Negro'') is one of the 21 forests that make up the public forests system in Puerto Rico. It is also Puerto Rico's highest cloud forest. It is in the Cordillera Central, Puerto Rico, Cord ...

. It is a federally listed

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

of the United States. This fern was first described in 1985.Proctor, G. R. (1985)
New species of ''Thelypteris'' from Puerto Rico.
''American Fern Journal'' 75(2) 56-70. It was placed on the endangered species list in 1993.USFWS
Determination of endangered status for three endemic Puerto Rican ferns.
''Federal Register'' July 2, 1993. At that time it was known to exist at two locations in the mountain forests of Puerto Rico, one near the Río Inabón in the

Toro Negro Commonwealth Forest Toro Negro State Forest (Spanish: ''Bosque Estatal de Toro Negro'') is one of the 21 forests that make up the public forests system in Puerto Rico. It is also Puerto Rico's highest cloud forest. It is in the Cordillera Central, Puerto Rico, Cord ...

and one on Cerro Rosa in

Ciales Ciales (, ) is a town and municipality of Puerto Rico, located on the Central Mountain Range, northwest of Orocovis; south of Florida and Manatí; east of Utuado and Jayuya; and west of Morovis. Ciales is spread over eight barrios and Cial ...

(Cerro Rosa is also located in the

''Los Bosque de Puerto Rico.''
PR Department of Natural and Environmental Resources. Hojas de Nuestro Ambiente. Publication P-010. November 2006. Retrieved 18 August 2013.). In total there were about 46 individual plants counted. This terrestrial fern has fronds up to 60 centimeters long divided into 25 or 30 pairs of lightly hairy segments. The sori are arranged around the veins on the undersides. They are covered with hairy indusia.

References

Thelypteridaceae Endemic flora of Puerto Rico Plants described in 1985 {{Polypodiales-stub