Becherfarn

Description

Cyathea australis, also known as the Rough Tree Fern, is a species of tree fern native to southeastern Queensland, New South Wales and southern Victoria in Australia, as well as Tasmania and Norfolk Island. 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. The massive erect trunk is usually up to 12 m tall, although specimens reaching 20 m have been reported from Queensland, Australia. Fronds 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. The Tree Fern has quite 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 Cyathea 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. C. australis is a highly variable taxon, with several subspecies and varieties. Individuals from the Norfolk Island subspecies, norfolkensis, are larger and more robust, differing primarily in scale characteristics. C. australis ssp. norfolkensis is rare in cultivation. Further study is needed to determine whether this taxon represents a separate species or not. C. australis was described in 1810 by Robert Brown from a specimen collected on King Island in Bass Strait, off the coast of Tasmania. It is the type for the genus Alsophila, which has now been reduced to a section. The specific epithet australis means "southern" and refers to this southerly location.