Alsophila australis

Species of fern
Speciesbox
| image = Cyathea australis 1. jpg
| image caption =
| genus = Alsophila (plant)
| species = australis
| authority = R. Br. Plants growing in southern Australia often lose their fronds by the end of winter, as is the case with Alsophila dregei in South Africa. 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 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.

Joseph Maiden 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."

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 of up to 1280 m, often in the company of Dicksonia antarctica. 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.

In the horticultural 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.