''Cyathea croftii'' is a species of

tree fern The tree ferns are arborescent (tree-like) ferns that grow with a trunk elevating the fronds above ground level, making them trees. Many extant tree ferns are members of the order Cyatheales, to which belong the families Cyatheaceae (scaly tree ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Manus Island Manus Island is part of Manus Province in northern Papua New Guinea and is the largest of the Admiralty Islands. It is the fifth-largest island in Papua New Guinea, with an area of , measuring around . Manus Island is covered in rugged jungles w ...

in the

Admiralty Islands The Admiralty Islands are an archipelago group of 18 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-co ...

, 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 A frond is 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. Other botanists allow the term frond to also apply to the lar ...

bi- Numeral or number prefixes are prefixes derived from numerals or occasionally other numbers. In English and many other languages, they are used to coin numerous series of words. For example: * unicycle, bicycle, tricycle (1-cycle, 2-cycle, 3-cy ...

tripinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and in ...

and 2–3 m long. The

rachis In biology, a rachis (from the grc, ῥάχις [], "backbone, spine") is a main axis or "shaft". In zoology and microbiology In vertebrates, ''rachis'' can refer to the series of articulated vertebrae, which encase the spinal cord. In this c ...

and stipe are often light green, particularly when young. They are slender and covered with glossy brown scales towards the base. Sori are small and occur in rows, one along each side of the

pinnule A leaflet (occasionally called foliole) in botany is a leaf-like part of a compound leaf. Though it resembles an entire leaf, a leaflet is not borne on a main plant stem or branch, as a leaf is, but rather on a petiole or a branch of the leaf. Co ...

midvein. They are covered by thin

indusia A sorus (pl. sori) is a cluster of sporangia (structures producing and containing spores) in ferns and fungi. A coenosorus (plural coenosori) is a compound sorus composed of multiple, fused sori. Etymology This New Latin word is from Ancient Gr ...

. The specific

epithet An epithet (, ), also byname, is a descriptive term (word or phrase) known for 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, di ...

''croftii'' commemorates

pteridologist #REDIRECTFern 01 Ferns Pteridologist #REDIRECTFern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The ...

James R. Croft (b. 1951).

References

*Braggins, John E. & Large, Mark F. 2004. ''Tree Ferns''. Timber Press, Inc., p. 118.
The International Plant Names Index: ''Cyathea croftii''
* croftii Endemic flora of New Guinea Flora of the Bismarck Archipelago Plants described in 1982 {{Cyatheales-stub