Eucalyptus microtheca F. Muell.
Flooded box, Coolibah
Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.
- Folk Medicine
- Yields and Economics
This tall tree, featured in the song, "Waltzing Matilda", produces one of the
hardest and strongest timbers in the world. The wood is, however, difficult to
work because of the interlocking grain. Unsuitable for construction, it makes
durable poles and fence posts. Little (1983) suggests that the wood is
suitable for bearings, bushings, bolts, shafts, frames, and wheel parts for
heavy vehicles. The tree is esteemed for erosion control, shade and soil
conservation in hot arid climates. Aborigines obtained water from the
superficial roots, by cutting forearm-sized root segments, then holding them
vertically, after debarking. Sometimes they blew into the distal portion to
enhance the flow. Aborigines use the branch and leaf as a fish poison (Watt
and Breyer-Brandwijk, 1962).
Reported to be antiseptic and disinfectant, the inner bark is a folk remedy
poulticed onto snakebite.
Leaves contain 0.49% essential oil with cineol, phallandrene, and pinene. The
bark contains ca 6% tannin (Watt and Breyer Brandwijk, 1962).
Evergreen tree 620 m high, usually crooked or irregular, 30100 cm in
diameter. Bark gray or brackish, thick, fibrous, rough, not shedding. Leaves
alternate, narrowly lanceolate, 620 cm long, 13 cm wide, acuminate apically,
basally acute, not entire, glabrous, slightly thick, leathery, dull green,
slightly paler underneath. Panicles mostly near ends of twigs, short, branched
with slightly angled slender stalks ending in umbels of 37 short stalked
fragrant flowers. Flowers very small, the bud 46 mm long. Stamens many,
spreading, white, short, 34 mm long, anthers rounded with small round gland.
Pistil with inferior 34-celled ovary and stout style. Capsules short-stalked,
hemiglobose or turbinate, very small, 34.5 mm long and wide. Seeds many,
tiny, 2 mm long, blackish (Little, 1983).
Reported from the Australian Center of Diversity, coolibah, or cvs thereof, is
reported to tolerate alkalinity, clay, drought, fungus, heat, heavy soil, high
pH, insect, savanna, waterlogging, and wind (NAS, 1980a; Little, 1983). Trees
will not tolerate fires, especially when young.
Widely distributed in Australia (except Victoria and Tasmania) in open
woodlands, floodplains, seasonally flooded areas, and the edges of swamps,
coolibah has been successfully introduced to Egypt, Iran, Iraq, Nigeria,
Pakistan, Sudan, and Tanzania.
Estimated to range from Tropical Thorn to Tropical Very Dry (Little also
suggests Tropical Moist) through Warm Temperate Thorn to Dry Forest Life Zones,
coolibah is estimated to tolerate annual precipitation of 2 to 12 dm, annual
temperature of 17 to 25°C, and pH of 6.0 to 8.2. Mean maximum temperatures
in the hottest months are 3538°C; mean minimum in the coolest, ca 5°C.
It can withstand a few light frosts. In its native range it grows between
80700 m elev. on clays or silty clay loams, often alkaline.
Easily propagated by seeds, seedlings are outplanted at ca 6 mos. when they are
ca 4 dm tall. Seeds must be exposed to light during germination. Trees must
be carefully weeded until they are well established.
The tree coppices well. In the Gezira, the seedling crop is harvested in 8
years, then harvested on a 6-year coppice rotation.
The tree may grow 3 m a year (in height). Wood yield of 5 to m3/ha/yr are
reported (Webb et al., 1980).
Making an excellent firewood, coolibah is cultivated as such in the Sudan, for
example. It makes a fairly good charcoal with a relatively high ash content
Complete list of references for Duke, Handbook of Energy Crops
- Little, E.L. Jr. 1983. Common fuelwood crops: a handbook for their
identification. McClain Printing Co., Parsons, WV.
- N.A.S. 1980a. Firewood crops. Shrub and tree species for energy production.
National Academy of Sciences, Washington, DC.
- Watt, J.M. and Breyer-Brandwijk, M.G. 1962. The medicinal and poisonous plants
of southern and eastern Africa. 2nd ed. E.&S. Livingstone, Ltd., Edinburgh
- Webb, D.E., Wood, P.J., and Smith, J. 1980. A guide to species selection for
tropical and sub-tropical plantations. Tropical Forestry Papers 15. CFI, Oxford.
Last update Tuesday, January 6, 1998 by aw