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Plant Profile

Palma Manaca (Calyptronoma rivalis)

This is a full shot of the small Palma de manaca. It grows to 30-40 feet, with a smooth trunk 6 to 10 inches in diameter. Photo Credit: Jennifer Possley
  • Global Rank: G1 - Critically Imperiled
  • Legal Status: Federally Threatened
  • Family: Arecaceae
  • State: PR
  • Nature Serve ID: 138932
  • Date Inducted in National Collection: 01/01/1985

Calyptronoma rivalis grows along stream banks in the semi-evergreen forests of the karst region in Puerto Rico and can reach up to 12 meters in height (USFWS 1992). The palm has dioecious flowers that bloom twice a year and produce an abundant amount of small reddish fruits (Vivaldi and Woodbury 1981). This palm is threatened by flooding caused by deforestation, agricultural expansion and rural development (USFWS 1992).

Where is Palma Manaca (Calyptronoma rivalis) located in the wild?


Calyptronoma rivalis grows in the semi-evergreen, subtropical moist forests in either the limestone or karst region of northwestern Puerto Rico (USFWS 1992). A well-developed understory and two to three tree strata are characteristic of the semi-evergreen forests in the limestone region (USFWS 1992). Adjacent areas are agricultural and contain crops such as coffee, yams, bananas and sugar cane (Vivaldi and Woodbury 1981, Silander et al. 1986). The karst region boasts a diverse topography, ranging from extremely rugged cliffs and canyons to smaller hills (USFWS 1992). In both of these areas, Calyptronoma rivalis is found growing along the stream banks. In the forests of the limestone region, Calyptronoma rivalis is associated with the introduced species Syzygium jambos (pomarrosa) and native species Andira inermis (moca), Roystonea boringuena (palma real), and Guarea guidonia (guaraguao) (USFWS 1992).


Calyptronoma rivalis is endemic to Puerto Rico (Bailey 1938, Vivaldi and Woodbury 1981, Henderson 1984 and USFWS 1992).

States & Provinces:

Palma Manaca can be found in Puerto Rico

Which CPC Partners conserve Palma Manaca (Calyptronoma rivalis)?

CPC's Plant Sponsorship Program provides long term stewardship of rare plants in our National Collection. We are so grateful for all our donors who have made the Plant Sponsorship Program so successful. We are in the process of acknowledging all our wonderful plant sponsorship donors on our website. This is a work in progress and will be updated regularly.

Conservation Actions

Nature Serve Biotics
  • 05/02/2017

Known from 2 populations with few individuals left. Little and Wadsworth, 1980, include the following: The species has been known from only about 20 plants of all sizes growing along a marshy stream about 3 miles east of San Sebasti?n in northwestern Puerto Rico. It is reported that a second grove nearby might have been destroyed by clearing. Recently, Woodbury has discovered another grove in Tanama River Gorge near Quebradillas.

  • 01/01/2010

Primary threats include deforestation, road building, grazing and agriculture (USFWS 1992).

  • 01/01/2010

Calyptronoma rivalis is known from three privately owned sites that support about 275 individuals (USFWS 1992).

  • 01/01/2010

The Botanical Gardens of the University of Puerto Rico and the Fairchild Tropical Garden in Miami, Florida are both successfully propagating this palm (USFWS 1992).

  • 01/01/2010

The Puerto Rico Department of Natural Resources has reintroduced Calyptronoma rivalis into two areas (USFWS 1992).

  • 01/01/2010

The U.S. Fish and Wildlife Service (1992) proposes to delist Calyptronoma rivalis when populations are sufficiently protected and when at least three new established are self-sustaining. Additional management and research needs include prevention of further habitat destruction, population monitoring, enforcement of endangered species regulations, habitat and germination requirements and reproductive biology and ecology (USFWS 1992).


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Taxon Calyptronoma rivalis
Authority (O.F. Cook) Bailey
Family Arecaceae
CPC Number 701
ITIS 42442
Common Names Palma de Manaca | Palma Manaca | Puerto Rican manac | manac palm
Associated Scientific Names Calyptrogyne rivalis | Calyptronoma rivalis
Distribution Calyptronoma rivalis is endemic to Puerto Rico (Bailey 1938, Vivaldi and Woodbury 1981, Henderson 1984 and USFWS 1992).
State Rank
State State Rank
Puerto Rico S2
Ecological Relationships

Bees and wasps have been observed visiting the flowers of this palm, but their role in pollination is unknown (USFWS 1992).

Common Name Name in Text Association Type Source InteractionID
Bees Suspected Pollinator Floral Link
Wasps Suspected Pollinator Floral Link

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