Palma de Manaca

Calyptronoma rivalis

Description

Palma de manaca, Calyptronoma rivalis, is a palm tree that weighs about 25 lb (11.4 kg) and reaches about 30-40 ft (9-12 m) in height. Its trunk is smooth and may grow to 6-10 in (15-25 cm) in diameter. Also called manac palm, palma de manaca has spineless, feather-shaped leaves which can reach up to 12 ft (3.7 m) long, with a leaf stalk of 2 ft (0.6 m) long and a sheath of 2 ft (0.6 m) long. Its large flowers are clustered, branched, and drooping. Borne on sunken pits, these flowers are arranged in triads of two males and one female. The fruits, less than 0.25 in (6.4 mm) wide, are imperfectly round and reddish when ripe. All of the fruits mature at the same time and fall with the persistent flower parts still attached to the base.

Habitat

All three natural populations are located in the semievergreen, limestone forests of northwestern Puerto Rico. These forests are at elevations of 325-500 ft (100-150 m). The habitat areas are wet and humid, and the natural populations are found in level or almost level areas around stream banks. These palm trees will grow in sun or shade. In the upper part of the Rio Camuy, some individuals are located at the bottom of deep canyons.

Distribution

Until 1980, this palm tree was known from only one site, Quebrada Collazo, a small stream near San Sebastian in northwestern Puerto Rico. Only 44 individuals remain there. Two additional populations have been discovered during the late twentieth century; one site, along the Camuy River, was discovered in 1980. The other site, along the Guajataca River, was found later. The combined population at these two sites is 220 individuals. In addition, two new populations have been established from palm tree seedlings, one in the Puerto Rican Department of Natural Resources' Rio Abajo Commonwealth Forest and the other at Camp Guajataca, owned by the Boy Scouts.

Threats

Deforestation for road construction and pastures, flash floods, and fires are the most serious threats. Coffee plantations, pastures, and other deforested areas surround the largest population site of 200 individuals around the River Camuy. Because of the deforestation, these areas are susceptible to flash floods and new seeds and seedlings are frequently washed away and/or stream banks are eroded. A large segment of the adult population around northern River Camuy was destroyed during road construction on the east side of the river. At the oldest population site around Quebrada Collazo, sugar cane fires have killed several plants. This area also consists of deforested pasture land, and cattle may eat or trample on new tree seedlings. Periodic floods also occur in the area.

Conservation and Recovery

The Quebrada Collazo area is owned by private individuals. Part of the area is owned by a family that has protected the plants on their property for many years. Sections of the other two natural populations are both publicly and privately owned. In 1979 the Puerto Rican Department of Natural Resources issued a directive to protect these palm trees; as yet, however, this species has not been added to the Commonwealth list. One population each has been introduced into the Rio Abajo Commonwealth Forest and in Camp Guajataca. Although the introduction effort inside the forest was successful, it is unknown whether the plants will reproduce and colonize the area naturally.

Contacts

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
1875 Century Blvd., Suite 200
Atlanta, Georgia 30345
http://southeast.fws.gov/

U. S. Fish and Wildlife Service
Boquerón Ecological Services Field Office
P. O. Box 491
Boquerón, Puerto Rico 00622-0491
Telephone: (787) 851-7297
Fax: (787) 851-7440

References

Ayensu, E. S., and R. A. DeFilipps. 1978. Endangered and Threatened Plants of the United States. Smithsonian Institution and World Wildlife Fund, Washington, D.C. 403 p.

Little, E., R. O. Woodbury, and F. H. Wadsworth.1974. "Trees of Puerto Rico and the Virgin Islands." U. S. Department of Agriculture, Forest Service Handbook 449.

U. S. Fish and Wildlife Service. 6 February 1990. "Determination of Threatened Status for the Plant Calyptronoma rivalis. " Federal Register 55 (25): 4157-4159.

Woodbury, R. O. 1975. "The Rare and Endangered Plants of Puerto Rico." U. S. Department of Agriculture, Soil Conservation Service, and Puerto Rico Department of Natural Resources. 85 p.