Cyathea decrescens 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 Madagascar

Madagascar

The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...

. The trunk is erect, 2-3 m tall and 10-12 cm in diameter. It usually has characteristic elliptical scars caused by fallen 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....

 bases. 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 and 1-1.5 m long. The fronds may be densely pubescent and the lower pinnules are sometimes separated from the others as well as being reduced. 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 are brown in colouration and bear narrow, dark 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. 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 large, round and covered by fragile, brown indusia.