Tree fern
Tree Fern refers to any fern that grows with a trunk elevating the fronds above ground level. Most tree ferns compose a group of large primitive ferns belonging to the families Dickensoniaceae and Cyathiaceae.
Tree Fern (Dicksonia antarctica)
in an English garden. The trunk is
two feet high (60 cm).
Tree ferns are found growing in tropical and subtropical areas, including cool to temperate rainforest in Australia, New Zealand and neighbouring regions (eg Malaysia, Lord Howe Island etc). Like all ferns, tree ferns reproduce by means of spores formed on the undersides of the fronds.
The fronds of tree ferns are usually very large and multiply-pinnate. One type, however, has entire (undivided) fronds.
Unlike flowering plants, tree ferns do not form new woody tissue in its trunk as it grows. Rather, the trunk is supported by a fibrous mass of roots that expands as the tree fern grows.
A tree fern can often be transplanted by cutting it off at the base of the trunk and replanting it elsewhere. If it is kept moist then it will regrow a new root system over the next year. The success rate of transplantation increases to about 80% if the roots are dug up intact. If the crown of a tree fern is damaged it will inevitably die because that is where all the new growth occurs (Tree fern trunks rarely fork).
A few ferns in other groups may be considered tree ferns, such as several ferns in the family Osmundaceae.
