''Alsophila australis'',

synonym 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 ...

''Cyathea australis'', also known as the rough tree fern, 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 southeastern

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

and southern Victoria in

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

, as well as

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

and

Norfolk Island Norfolk Island ( , ; ) is an States and territories of Australia, external territory of Australia located in the Pacific Ocean between New Zealand and New Caledonia, directly east of Australia's Evans Head, New South Wales, Evans Head and a ...

. It was known as ''beeow-wang'' in

Illawarra The Illawarra is a coastal Regions of New South Wales, region in the southeast of the Australian state of New South Wales. It is situated immediately south of Sydney and north of the South Coast, New South Wales, South Coast region. It encompas ...

, as ''pooeet'' at Corranderrk Station in Victoria, and as ''nanga-nanga'' in Queensland.

Taxonomy

''Alsophila australis'' was described in 1810 by

Robert Brown Robert Brown may refer to: Robert Brown (born 1965), British Director, Animator and author Entertainers and artists * Washboard Sam or Robert Brown (1910–1966), American musician and singer * Robert W. Brown (1917–2009), American printmaker ...

from a specimen collected on King Island in

Bass Strait Bass Strait () is a strait separating the island state of Tasmania from the Mainland Australia, Australian mainland (more specifically the coast of Victoria (Australia), Victoria, with the exception of the land border across Boundary Islet). The ...

, off the coast of Tasmania. It is a member of the genus '' Alsophila''. The specific

epithet An epithet (, ), also a byname, is a descriptive term (word or phrase) commonly accompanying or occurring in place of the name of a real or fictitious person, place, or thing. It is usually literally descriptive, as in Alfred the Great, Suleima ...

''australis'' means 'southern' and refers to this southerly location. ''Alsophila australis'' is a highly variable

taxon 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 ...

. Individuals from the

subspecies, ''A. australis'' ssp. ''norfolkensis'', are larger and more robust, differing primarily in scale characteristics. The subspecies is rare in cultivation. Further study is needed to determine whether this

represents a separate species or not.

Description

The massive erect trunk is usually up to 12 m tall, although specimens reaching 20 m have been reported from Queensland, Australia.

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 bi- or tripinnate and may reach 4 m in length, occasionally even 6 m. These form a distinctive crown that is dark green above and lighter green below. It has adventitious roots, tubercles and hair-like follicles on its 'trunk'. Plants growing in southern Australia often lose their fronds by the end of winter, as is the case with '' Alsophila dregei'' in

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

. Characteristically of this species, stipe bases are often retained around the trunk long after withering. They are covered with scales and conical, blunt spines towards the base. The scales range in colour from shiny brown to bicoloured (pale and brown) and are often distinctly twisted. The sori are circular and occur on either side of the 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 ...

midvein. True indusia are absent, although reduced scales may encircle the sori. In its montane range, ''A. australis'' is ecologically important as it provides the nesting substrate for '' Exoneura robusta'', a native species of reed bee. These bees almost exclusively build their nests in the pith of dead ''A. australis'' fronds. This species of bee is an important pollinator of other plants in southeastern Australia, so thus it can be seen how ''A. australis'' is indirectly supportive of other plants in its ecosystem.

Traditional use

Joseph Maiden Joseph Henry Maiden (25 April 1859 – 16 November 1925) was a botanist who made a major contribution to knowledge of the Australian flora, especially the genus ''Eucalyptus''. This botanist is denoted by the author abbreviation when citing ...

recorded in 1889 that "The pulp of the top of the trunk is full of starch, and is eaten raw and roasted by the aboriginals. This whitish substance is found in the middle of the tree from the base to the apex, and when boiled tastes like a bad turnip. Pigs feed on it greedily."

Cultivation

''Alsophila australis'' is a robust tub plant and tolerant of salty winds. It is a popular cool climate hardy tree-fern, adaptable to a variety of climates and soils. It grows in moist shady forest, both coastal and montane, at an altitude up to , often in the company of ''

Dicksonia antarctica ''Dicksonia antarctica'', the soft tree fern, Tasmanian Tree Fern or man fern, is a species of evergreen tree fern native to eastern Australia, ranging from south-east Queensland, coastal New South Wales and Victoria to Tasmania. Anatomy and ...

''. It is a relatively hardy species and a popular landscape and container plant. Provided moisture levels remain high, it will tolerate frost and full sun, or shade in warmer regions. Although well known in its native country, this species is not common in cultivation outside of Australia.

Horticulture

In the

horticultural Horticulture (from ) is the art and science of growing fruits, vegetables, flowers, trees, shrubs and ornamental plants. Horticulture is commonly associated with the more professional and technical aspects of plant cultivation on a smaller and mo ...

trade, most plants labeled as ''Alsophila australis'' are in fact '' Sphaeropteris cooperi''. Much confusion has existed between the two, especially in the United States, despite the two species being quite distinct from one another. ''A. australis'' is relatively stout trunked and has a large number of closely spaced fronds emerging at one time, with a slower increase in trunk height. ''S. cooperi'' in contrast, grows more quickly with fewer fronds emerging each year and has a much narrower trunk, with the frond bases aligned vertically for some distance ('hugging' the trunk, as it were) before arching outwards.

References

UNEP-WCMC Species Database: ''Cyathea australis''
{{Taxonbar, from1=Q17185344, from2=Q738235 australis Flora of New South Wales Flora of Queensland Flora of Tasmania Flora of Victoria (state) Flora of Norfolk Island Ferns of Australia Trees of Australia Ornamental trees Trees of mild maritime climate Plants described in 1810