Dicksonia antarctica
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2008-07-16T00:48:49Z
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{{Taxobox
| name = ''Dicksonia antarctica''
| image = Ferns.jpg
| image_width = 240px
| image_caption = ''Dicksonia antarctica'' in natural habitat in [[Gippsland]], Australia.
| regnum = [[Plant]]ae
| divisio = [[Pteridophyta]]
| classis = [[Pteridopsida]]
| ordo = [[Cyatheales]]
| familia = [[Dicksoniaceae]]
| genus = ''[[Dicksonia]]''
| species = '''''D. antarctica'''''
| binomial = ''Dicksonia antarctica''
| binomial_authority = [[Jacques Labillardière|Labill.]] 1807
}}
'''''Dicksonia antarctica''''', known as the Soft Tree Fern, Man Fern or Tasmanian Tree Fern is an evergreen [[tree fern]] native to parts of [[Australia]], namely [[New South Wales]], [[Tasmania]], and [[Victoria (Australia)|Victoria]].
== Anatomy and biology ==
These ferns can grow to 15 m in height, but more typically grow to about 4.5-5 m, and consist of an erect [[rhizome]] forming a trunk. They are very hairy at the base of the [[stipe (botany)|stipe]] (trunk). The large, dark green, roughly-textured [[frond]]s spread in a canopy of 2-6 m in diameter. The shapes of the stems vary as some grow curved and there are multi-headed ones. The fronds are borne in flushes, with fertile and sterile fronds often in alternating layers.
The "trunk" of this fern is merely the decaying remains of earlier growth of the plant and forms a medium through which the roots grow. The trunk is usually solitary, without runners, but may produce offsets. They can be cut down and, if they are kept moist, the top portions can be replanted and will form new [[root]]s. The stump, however, will not regenerate since it is dead organic matter. In nature, the fibrous trunks are hosts for a range of [[Epiphyte|epiphytic]] plants including other ferns and [[moss]]es.
The fern grows at 3.5 to 5 cm per year and produces [[spore]]s at the age of about 20 years.
=== Reproduction ===
Reproduction by this species is primarily from spores, but it can also be grown from plantlets occurring around the base of the rhizome.
In cultivation, it can also be grown as a "cutting", a method not to be encouraged unless the tree-fern is doomed to die in its present position. This involves sawing the trunk through, usually at ground level, and removing the fronds; the top part will form roots and regrow, but the base will die.
=== Habitat ===
The fern grows on damp, sheltered woodland slopes and moist gullies, and they occasionally occur at high altitudes in cloud forests. ''Dicksonia antarctica'' is the most abundant tree fern in South Eastern Australia.
The plant can grow in acid, neutral and alkaline [[soil]]s. It can grow in semi-shade. It strongly resents drought or dryness at the roots, but does best in moist soil.
== Cultivation ==
[[Image:Dicksonia antarctica Cultivated GardenEngland.jpg|right|thumb|''Dicksonia antarctica'' in an English garden. The trunk is 60 cm high.]]
It is particularly suited to garden planting and landscaping purposes. As an [[ornamental plant]], it is hardy to about –5 C, succeeding outdoors in the milder areas of [[Great Britain|Britain]] where it thrives and often self-sows in [[Cornwall|Cornish]] gardens.
It is best to leave old fronds on the plant in order to protect the trunk from cold and [[desiccation]]. Winter protection of the trunk is recommended during prolonged or severe cold weather.
They grow best in areas of rainfall of over 1,000 mm per year but in lower rainfall areas do well in moist gullies. They are tolerant of fire and re-shoot readily after re-location. This plant can provide habitat for epiphytes and also provides shelter for more delicate fern species to flourish underneath.
Plant in organic soils and heavily and regularly mulched and water. ''Dicksonia antarctica'' generally requires a minimum rainfall of 500 mm (20 inches) per year. In dry climates, a drip irrigation or spray system applied overhead is the most effective method of watering.
===Harvesting===
Large ''Dicksonia antarctica'' available for sale come from [[old growth]] Tasmanian forests, and may be hundreds of years old. The logging practices by the company [[Gunns]], who effectively have a state-monopoly on logging and make these plants available, have been criticized by green groups for several decades.<ref name=flanagan>{{cite journal | last = Flanagan | first = Richard | authorlink = Richard Flanagan | title = Out of control: the tragedy of Tasmania's forests | journal = The Monthly | volume = 23 | pages = 20–31 | date = May 2007}}</ref>
===Edibility===
[[Image:Ferns02.jpg|right|thumb|Dicksonia antarctica]]
The Soft Tree Fern can be used as a food source, with the [[pith]] of the plant being eaten either cooked or raw. It is a good source of [[starch]].
== References ==
* [http://www.ibiblio.org/pfaf/cgi-bin/arr_html?Dicksonia+antarctica Plants For a Future: ''Dicksonia antarctica'']
* [http://www.anbg.gov.au/gnp/interns-2003/dicksonia-antarctica.html Australian National Botanic Gardens: ''Dicksonia antarctica'' – the soft tree fern]
* Braggins, John E. and Large, Mark F. ''Tree Ferns''. Timber Press (2004). ISBN
{{Reflist}}
[[Category:Pteridophyta of Australia]]
[[Category:Flora of New South Wales]]
[[Category:Flora of Tasmania]]
[[Category:Flora of Victoria]]
[[Category:Trees of Australia]]
[[Category:Trees of mild maritime climate]]
[[Category:Ornamental trees]]
[[es:Dicksonia antarctica]]
[[nl:Tasmaanse boomvaren]]