Cyathea croftii 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...

 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 Manus Island

Manus Island

Manus Island is part of Manus Province in northern Papua New Guinea and is the largest island of the Admiralty Islands. It is the fifth largest island in Papua New Guinea with an area of 2,100 km², measuring around 100 km × 30 km. According to the 2000 census, Manus Island had a...

 in the Admiralty Islands

Admiralty Islands

The Admiralty Islands are a group of eighteen islands in the Bismarck Archipelago, to the north of New Guinea in the south Pacific Ocean. These are also sometimes called the Manus Islands, after the largest island. These rainforest-covered islands form part of Manus Province, the smallest and...

, where it grows in damp forest on steep slopes at an altitude of about 500 m. It is relatively uncommon in the wild. The trunk is erect, up to 3 m tall and about 6 cm in diameter. 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 bi- or tripinnate and 2–3 m long. 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....

 are often light green, particularly when young. They are slender and covered with glossy brown 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 towards the base. 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 small and occur in rows, one along each side of the pinnule midvein. They are covered by thin indusia.

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...

 croftii commemorates pteridologist James R. Croft (b. 1951).