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BATS
AND THE HORSETAIL TREE |
The Marianas flying fox is credited by Fujita (1991) with pollination of the flowers of the horsetail or ironwood tree which grows on the coasts of many tropical lands.
Marianas flying fox
Fujita and Usher (1974) list timber as the main contribution of the horsetail tree.
The timber has been used for hundreds of years in construction and for fuel. Horsetail tree charcoal is particularly valuable as fuel. The heat output of the charcoal is one of the highest among tree species. The fallen leaves and twigs of the tree are also used as fuel.
Australian aborigines made boomerangs from horsetail tree timber. The wood is used for shingles, tool handles, ships' masts, pilings and fencing.
Horsetail tree pulp is used to make paper and rayon.
Malaekahana, Oahu, Hawaii
Photograph courtesy of Forest & Kim Starr (USGS)
Those valuable uses aside, the horsetail tree joins with a number of other bat-pollinated and planted trees in being a vigorous colonizer in challenging environments. It grows readily in impoverished soils and on coastal areas buffeted by strong salt-laden winds.
Like the bat-pollinated beach gardenia and mangrove forests the coastal growth of the horsetail tree protects inland settlements and agriculture. Coastal stands of the horsetail tree prevent blown sand from burying roads and clogging irrigation canals. The trees hold back sand dunes from marching inland and reduce salt deposition on agricultural soils.
If the horsetail tree is interplanted with crops, it provides them with protection from the wind. The tree can also support valuable climbing plants such as vanilla.
Puu Ku, Maui, Hawaii
Photograph courtesy of Forest & Kim Starr (USGS)
One reason the horsetail tree can thrive in difficult growing circumstances is because of its botanical design. The tree's leaves resemble pine needles and grow in a circle at stem joints, thus its comparison to the perennial, herbaceous horsetail or scouring rush in the Equisetum genus.
The horsetail tree has a languid, weeping appearance which belies its established ability to provide shelter against adverse weather. Horsetail tree hedges and windbreaks are planted to protect coastal resorts.
Medicine: Washed and scraped horsetail tree roots, mixed with water and boiled, create a decoction which can reduce simple diarrhea, battle the dire effects of dysentery and calm a stomach ache. An astringent preparation from the tree's bark can reduce bleeding from wounds.
References:
Britannica Concise Encyclopedia, 2004
Difficult Sites Are Home to Casuarina; http://v1.winrock.org/forestry/factpub/factsh/casuarina_sp.html
Fujita, M.S. 1991. Flying Fox (Chiroptera:Pteropodidae) Pollination, Seed Dispersal, and Economic Importance: A Tabular Summary of Current Knowledge, Resource Publication No. 2, Bat Conservation International
Oxford Encyclopedia of Trees of the World, Bayard Hora, Consulting Editor
Usher, George, A Dictionary of Plants Used by Man, Constable and Company Ltd, 1974
Using Casuarina; http://geography.berkeley.edu/ProgramCourses/CoursePagesFA2002