Dicksonia antarctica.
The Soft Tree Fern is in Family Dicksoniaceae.
A terrestrial fern found in S.E. Queensland where it often forms large colonies.
The large trunks often have epiphytes such as orchids and other ferns growing on them.
The thick, dark brown, soft fibrous trunk (rhizome) can be up to 15 m high.
It is covered with dense brown, aerial roots.
The upper part has the bases of dead fronds on it.
The crown, particularly the developing fronds, is covered with soft, reddish-brown hairs up to 4.5 cm long.
The long arching, tripinnately divided fronds can be up to 4.5 m long.
They are a shiny dark green above and paler underneath.
The frond stalks are up to 30 cm long, green or brownish, with a few red hairs at the base and a ridge underneath.
Individual leaflets are tough, up to 5 mm long and sometimes have a short stalk.
The leaves are lobed or have serrated margins that curl under slightly.
The final segments of fertile leaflets are cut about half way to the midrib – deeper than the sterile ones.
The midrib is hairy and ridged underneath.
Sporangia are in globular sori, about 1 mm across, on the edges of fertile leaflets.
The indusium is cup-shaped with half formed by the curled edge of the leaflet and the other half by a fold of tissue.
The indusium falls off when the spores are mature.
J.F.
