Calyptronoma rivalis is a pinnate

Pinnate

Pinnate is a term used to describe feather-like or multi-divided features arising from both sides of a common axis in plant or animal structures, and comes from the Latin word pinna meaning "feather", "wing", or "fin". A similar term is pectinate, which refers to a comb-like arrangement of parts...

ly compound leaved palm

Arecaceae

Arecaceae or Palmae , are a family of flowering plants, the only family in the monocot order Arecales. There are roughly 202 currently known genera with around 2600 species, most of which are restricted to tropical, subtropical, and warm temperate climates...

 species which is found in Haiti

Haiti

Haiti , officially the Republic of Haiti , is a Caribbean country. It occupies the western, smaller portion of the island of Hispaniola, in the Greater Antillean archipelago, which it shares with the Dominican Republic. Ayiti was the indigenous Taíno or Amerindian name for the island...

, the Dominican Republic

Dominican Republic

The Dominican Republic is a nation on the island of La Hispaniola, part of the Greater Antilles archipelago in the Caribbean region. The western third of the island is occupied by the nation of Haiti, making Hispaniola one of two Caribbean islands that are shared by two countries...

 and Puerto Rico

Puerto Rico

Puerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...

. Its common names include palma de manaca and Puerto Rican manac. C. rivalis stems grow singly and reach heights of 4–15 m, with stems 15–30 cm in diameter. It grows in waterlogged areas near the banks of streams; in Hispaniola

Hispaniola

Hispaniola is a major island in the Caribbean, containing the two sovereign states of the Dominican Republic and Haiti. The island is located between the islands of Cuba to the west and Puerto Rico to the east, within the hurricane belt...

 is occurs below 450 m above sea level, and Calyptronoma plumeriana

Calyptronoma plumeriana

Calyptronoma plumeriana is a pinnately compound leaved palm species which is found in Cuba, Haiti and the Dominican Republic. C. plumeriana stems grow singly and reach heights of 4–10 m, with stems 10–20 cm in diameter...

replaces it above that elevation.

This palm was added to the endangered species list

Endangered Species Act

The Endangered Species Act of 1973 is one of the dozens of United States environmental laws passed in the 1970s. Signed into law by President Richard Nixon on December 28, 1973, it was designed to protect critically imperiled species from extinction as a "consequence of economic growth and...

 of the United States in 1990, with a threatened status. At that time it was believed to be endemic to Puerto Rico and limited to three populations with an estimated 220 total individuals remaining. In 1995, botanists revised the taxonomy

Taxonomy

Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...

 of genus Calyptronoma, placing Calyptronoma quisqueyana in synonymy

Synonym (taxonomy)

In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...

 with the rare palm. Then the species included all of the individuals previously named C. quisqueyana, extending its distribution to the island of Hispaniola. There it is not uncommon. Furthermore, its numbers on Puerto Rico increased to over 500, and then it was introduced

Introduced species

An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...

 to a few new areas on the island. The United States Fish and Wildlife Service

United States Fish and Wildlife Service

The United States Fish and Wildlife Service is a federal government agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats...

 will not remove the palm from the endangered species list yet because its Puerto Rican members are on private land, are not protected, and in some cases, are not reproducing successfully. The plants are located on land that is threatened with habitat destruction from development and habitat degradation resulting from poor management

Land management

Land management is the process of managing the use and development of land resources. Land resources are used for a variety of purposes which may include organic agriculture, reforestation, water resource management and eco-tourism projects.-See also:*Sustainable land management*Acreage...

. The palm is more plentiful on Hispaniola, but its status there is not well known.