Cyathea imrayana is a species of tree fern

Cyatheales

The order Cyatheales is a taxonomic division of the fern subclass, Cyatheatae, which includes the tree ferns. No clear morphological features characterize all of the Cyatheales, but DNA sequence data indicates that the order is monophyletic. Some species in the Cyatheales have tree-like growth...

 native to Dominica

Dominica

Dominica , officially the Commonwealth of Dominica, is an island nation in the Lesser Antilles region of the Caribbean Sea, south-southeast of Guadeloupe and northwest of Martinique. Its size is and the highest point in the country is Morne Diablotins, which has an elevation of . The Commonwealth...

, Costa Rica

Costa Rica

Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....

, Panama

Panama

Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...

, Venezuela

Venezuela

Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...

, and Ecuador

Ecuador

Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...

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The plant grows in submontane rain forest understory

Understory

Understory is the term for the area of a forest which grows at the lowest height level below the forest canopy. Plants in the understory consist of a mixture of seedlings and saplings of canopy trees together with understory shrubs and herbs...

 and riparian zone

Riparian zone

A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the fifteen terrestrial biomes of the earth. Plant habitats and communities along the river margins and banks are called riparian vegetation, characterized by...

s on riverbanks, at an altitude of 1000–2000 m (3,280.8–6,561.7 ft).

Description

Cyathea imrayana is species with an erect trunk that is 8–10 m (26.2–32.8 ft) tall and 10–15 cm (3.9–5.9 in) in diameter. It is covered with sharp, blackish spines and pale brown hairs. Frond

Frond

The term frond refers to a large, divided leaf. In both common usage and botanical nomenclature, the leaves of ferns are referred to as fronds and some botanists restrict the term to this group...

s are bipinnate, 2–3 m (6.6–9.8 ft) in length, and occur in whorls of five. The crown is large and spreading, especially in young plants.

The rachis

Rachis

Rachis is a biological term for a main axis or "shaft".-In zoology:In vertebrates a rachis can refer to the series of articulated vertebrae, which encase the spinal cord. In this case the rachis usually form the supporting axis of the body and is then called the spine or vertebral column...

 and stipe

Stipe (botany)

In botany, a stipe is a stalk that supports some other structure. The precise meaning is different depending on which taxonomic group is being described....

 range in colouration from brown to dark brown and bear bicoloured scale

Scale (zoology)

In most biological nomenclature, a scale is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopteran species, scales are plates on the surface of the insect wing, and provide coloration...

s (brown center and paler margin) with a terminal seta

Seta

Seta is a biological term derived from the Latin word for "bristle". It refers to a number of different bristle- or hair-like structures on living organisms.-Animal setae:In zoology, most "setae" occur in invertebrates....

. Scales on pinnule veins are whitish. Sori

Sorus

A sorus is a cluster of sporangia .In fungi and lichens, the sorus is surrounded by an external layer. In some red algae it may take the form of a depression into the thallus....

 are round and borne on either side of the pinnule midvein, towards the base of the pinnule segment. They are protected by red-brown, globose indusia.

Varieties
There are two distinct varieties

Variety (biology)

In botanical nomenclature, variety is a taxonomic rank below that of species: as such, it gets a three-part infraspecific name....

 of this species. One is Cyathea imrayana var. caribaea, which was originally described as a species. It is endemic

Endemic (ecology)

Endemism is the ecological state of being unique to a defined geographic location, such as an island, nation or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, all species of lemur are endemic to the...

 to the island of Saint Vincent

Saint Vincent (island)

Saint Vincent is a volcanic island in the Caribbean. It is the largest island of the chain called Saint Vincent and the Grenadines. It is located in the Caribbean Sea, between Saint Lucia and Grenada. It is composed of partially submerged volcanic mountains...

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The specific epithet

Epithet

An epithet or byname is a descriptive term accompanying or occurring in place of a name and having entered common usage. It has various shades of meaning when applied to seemingly real or fictitious people, divinities, objects, and binomial nomenclature. It is also a descriptive title...

 imrayana commemorates plant collector John Imray

John Imray

Dr. John Imray was a medical doctor, legislator, agriculturist and botanist. Born in Scotland he studied medicine at Edinburgh University and arrived in Dominica in 1832 to take up the only public medical post at the time: surgeon to the prison.Imray published papers on tropical diseases and...

 (1811-1880), who collected the type

Holotype

A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...

 material.

This Cyathea imrayana is not to be confused with Cyathea imrayana used as a synonym of Cnemidaria grandifolia

Cnemidaria grandifolia

Cnemidaria grandifolia is a species of tree fern whose natural distribution ranges from Trinidad and Tobago to the Paraguaná Peninsula in Venezuela. It grows at the edge of forests, on stream banks, and on mountainsides at an altitude of 300-1100 m....

((W. J. Hooker) Domin, 1929).