''Alsophila borbonica'',

synonym A synonym is a word, morpheme, or phrase that means exactly 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 all ...

''Cyathea borbonica'', is a

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 to

Mauritius Mauritius ( ; french: Maurice, link=no ; mfe, label=Mauritian Creole, Moris ), officially the Republic of Mauritius, is an island nation in the Indian Ocean about off the southeast coast of the African continent, east of Madagascar. It incl ...

and

Réunion Réunion (; french: La Réunion, ; previously ''Île Bourbon''; rcf, label= Reunionese Creole, La Rényon) is an island in the Indian Ocean that is an overseas department and region of France. It is located approximately east of the island ...

. There are several natural forms and varieties.

Description

It reaches a height of roughly 2 meters, with a dark, hairy, scaly trunk. Its spreading leaves are dark green fronds. Each frond has a relatively small stem ( stipe). Each leaf also divides only twice ( bipinnate): * The central midrib of the frond ( rachis) branches into many horizontal leaflets ( pinnae). * Each pinna midrib bears many small leaflets ( pinnules).

Forms and distribution

There are two natural Mauritian varieties, which occur mainly in the upland forest in the higher parts of the island, and are both endangered. There is one natural Reunionese variety: * ''A. borbonica var. borbonica'' (Réunion) * ''A. borbonica var. latifolia'' (Mauritius), which bears an umbrella-shaped crown * ''A. borbonica var. sevathiana'' (Mauritius), which bears a funnel-shaped crown

Related species

, they share the island with several other tree ferns - the naturally occurring Mauritian species ''

Alsophila grangaudiana Alsophila may refer to: * ''Alsophila'' (moth), a genus of moth * ''Alsophila'' (plant), a genus of tree ferns {{Taxonomy disambiguation ...

'' and ''

Alsophila celsa Alsophila may refer to: * ''Alsophila'' (moth), a genus of moth * ''Alsophila'' (plant), a genus of tree ferns {{Taxonomy disambiguation ...

'' - and the alien non-indigenous ''

Sphaeropteris cooperi ''Sphaeropteris cooperi'', synonym ''Cyathea cooperi'', also known as lacy tree fern, scaly tree fern, or Cooper's tree fern, is a tree fern native to Australia, in New South Wales and Queensland. Description ''Sphaeropteris cooperi'' is a me ...

'' which is introduced from its native

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. In

, they share the island with the naturally occurring Réunionese species ''

Alsophila glaucifolia ''Alsophila glaucifolia'', synonym ''Cyathea glauca'', is a species of tree fern endemic to Réunion. Little is known about this species. Habitat and related species ''A. glaucifolia'' grows at higher altitudes () and it is one of three species ...

'' and ''

Alsophila celsa Alsophila may refer to: * ''Alsophila'' (moth), a genus of moth * ''Alsophila'' (plant), a genus of tree ferns {{Taxonomy disambiguation ...

'' - and also with the introduced ''

''. ''Alsophila borbonica'' can be distinguished from all of these other species by its small stipe and by its fronds' two-level division.M. Glaubrecht (2010): ''Evolution in Action: Case studies in Adaptive Radiation, Speciation and the Origin of Biodiversity''. Springer Science & Business Media. Science. p.13. File:Funchal, Monte - Cyathea cooperi (Australischer Baumfarn) IMG 1893.JPG, The alien ''

'' can be distinguished by the red and white hairs on its new fronds. File:Cyathea glauca fronds.jpg, The tripinnate fronds of ''

'' in

References

External links

{{Taxonbar, from1=Q15576033, from2=Q3008067 Flora of Réunion Flora of Mauritius borbonica Plants described in 1811