Cyathea coactilis
Encyclopedia
Cyathea coactilis is a rare species of tree fern
known only from the southern highlands of Papua New Guinea
, where it grows in alpine shrubland at an altitude of about 3000 m. The trunk is erect and 2-3 m tall. Frond
s are bi- or tripinnate and usually 1-2 m long. Characteristically of this species, they occur in two whorls of about ten fronds each. The underside of the rachis
is covered with small, pale scale
s. The stipe
is covered with pale scales that have dark, narrow and fragile edges. Sori
are round and are covered by thin indusia that are cup-like in appearance. They occur near the fertile pinnule midvein.
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...
known only from the southern highlands of Papua New Guinea
Papua New Guinea
Papua New Guinea , officially the Independent State of Papua New Guinea, is a country in Oceania, occupying the eastern half of the island of New Guinea and numerous offshore islands...
, where it grows in alpine shrubland at an altitude of about 3000 m. The trunk is erect and 2-3 m tall. 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 bi- or tripinnate and usually 1-2 m long. Characteristically of this species, they occur in two whorls of about ten fronds each. The underside of 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...
is covered with small, pale 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. The 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....
is covered with pale scales that have dark, narrow and fragile edges. 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 are covered by thin indusia that are cup-like in appearance. They occur near the fertile pinnule midvein.