''Gymnosphaera biformis'',

synonyms A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...

''Alsophila biformis'' and ''Cyathea biformis'', is a species of

tree fern Tree ferns are arborescent (tree-like) ferns that grow with a trunk (botany), 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 ( ...

native to

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...

and the

Maluku Islands The Maluku Islands ( ; , ) or the Moluccas ( ; ) are an archipelago in the eastern part of Indonesia. Tectonics, Tectonically they are located on the Halmahera Plate within the Molucca Sea Collision Zone. Geographically they are located in West ...

, where it grows against trees in

mossy forest A cloud forest, also called a water forest, primas forest, or tropical montane cloud forest, is a generally tropical or subtropical, evergreen, montane, moist forest characterized by a persistent, frequent or seasonal low-level cloud cover, ...

and rain forest at elevations of 850–2200 m. The climbing trunk is very thin, only 1–2 cm in diameter, but can reach 3 m in height. The apex of the trunk is covered in scales. Two types of

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 ...

s are produced, simple

pinnate 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 ...

fronds, which are sterile, and

bipinnate The following terms are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (that is, the leaf blade or 'lamina' is undivided) or compound (that is, the leaf blade is divided into two or more leaflets ...

fronds, which may be fertile. The stipe is smooth, glossy and very dark, almost to the point of being black. It is covered at the base with long, very dark scales that have a pale margin. Fertile

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. C ...

s are distinctly stalked and lobed. Sori occur in four pairs per pinnule lobe and lack indusia. ''Gymnosphaera biformis'' is a very unusual species, being a climbing or scrambling fern with a very thin trunk. Plants often cling to supporting trees by their roots. The closest relative of this species appears to be '' Gymnosphaera scandens'', which differs only in the shape of its fertile pinnules. Further study is needed to determine whether the two are separate

taxa In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

or in fact represent the same species.

Taxonomy

Gepp published three names of

s with the

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

''arfakensis'': '' Alsophila arfakensis'', ''Cyathea arfakensis'' and ''Polybotrya arfakensis''. The last two are now considered to be synonyms of ''Gymnosphaera biformis'', whereas the first is a separate species. To transfer ''Cyathea arfakensis'' to ''Alsophila'', Tryon published the

replacement name In biological nomenclature, a ''nomen novum'' (Latin for "new name"), replacement name (or new replacement name, new substitute name, substitute name) is a replacement scientific name that is created when technical, nomenclatural reasons have mad ...

''Alsophila lilianiae'' since ''Alsophila arfakensis'' had already been used. ''Alsophila lilianiae'' became unnecessary when ''Cyathea arfakensis'' was considered a synonym of ''Gymnosphaera biformis''.

Taxonomy

References

Further reading