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 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.
