Common Name: Spotted Gum

General Information

Corymbia maculata is an evergreen tree with a large crown; it usually grows around 35 - 45 metres tall, with exceptionally large trees reaching 70 metres. The bole is distinctively straight and can be very long, it is usually 100 - 130cm in diameter, but sometimes reaches 300cm or more. On poorer sites the tree may only be 20 - 35 metres tall and 70 - 120cm in diameter[].
The tree is harvested from the wild for local use as a medicine and source of materials. Its wood is used commercially and the tree has been planted in many areas of the tropics and subtropics[]. It is also used in reforestation projects and to provide shelter, and is often grown as an ornamental, valued especially for its attractive makings on the trunk[].
Corymbia maculata has escaped from plantings in Western Australia and become naturalised there. This species is regarded as an environmental weed in Victoria, posing a serious risk to lowland grassland and associated woodlands, and dry sclerophyll forest and woodland, noting it as widespread but occurring in small populations[].

Known Hazards

None known

Botanical References

,

Range

Australia - Victoria, New South Wales, southern Queensland

Habitat

Open forests, on hilly country, in almost pure stands on the lower slopes of valleys and on ridges where the soil is fairly fertile and not too dry and on upper slopes of northerly facing aspect[].

Properties

Weed Potential	Yes
Medicinal Rating
Other Uses Rating
Habit	Evergreen Tree
Height	40.00 m
Growth Rate	Fast
Pollinators	Bees, Insects
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Corymbia maculata grows wild from the temperate to the subtropical zones and from the humid coastal plains to dry inland areas. It can be found at elevations up to 2,000 metres, growing in areas where the mean annual temperature ranges from 15 - 20°c, and the mean annual rainfall from 700 - 1,800mm[]. When dormant, the plant can survive temperatures down to about -6°c, but young growth is more tender and can be severely damaged at 0°c[].
Requires a sunny position[]. The tree grows best on moist, well-drained soils of moderately heavy texture. The parent material includes slates, shales and granites[]. Trees are tolerant of exposed, windy situations, even if there is salt spray[]. Prefers a pH in the range 5.5 - 6, tolerating 5 - 7[]. Established plants are drought tolerant[].
The plant develops a lignotuber - this is a woody tuber that starts to develop near the base of seedlings and can become massive in the mature plants of some species. It possesses embedded vegetative buds, allowing the plant to regenerate following crown destruction, for example by fire[].
The tree coppices well and can survive most forest fires by resprouting from the base[, ]. A fire-resistant species and, although young seedlings are sensitive to fire, well-established seedlings are resistant[].
The tree is cultivated for its wood in many countries. It grows fast and in South Africa, an average annual increase in height of 2 - 2.5 metres has been recorded in the first few years[].
Annual wood production potential is 21 - 35 cubic metres per hectare[].
Whilst most Corymbia species, grown in small numbers outside their native range, can be an attractive and useful addition to the landscape, certain species (including this one) are more problematic. When grown in monocultures, especially outside their native range, they can become an environmental disaster. They are voracious, especially in their use of water; they are allelopathic, inhibiting the growth of the native flora; they reduce habitats for native fauna; and encourage the worst possible attitudes to land use and conservation[].
Corymbia species have not adopted a deciduous habit and continue to grow until it is too cold for them to do so. This makes them more susceptible to damage from sudden cold snaps. If temperature fluctuations are more gradual, as in a woodland for example, the plants have the opportunity to stop growing and become dormant, thus making them more cold resistant. A deep mulch around the roots to prevent the soil from freezing also helps the trees to survive cold conditions[]. Many members of this genus are remarkably adaptable however, and there can be a dramatic increase in the hardiness of subsequent generations from the seed of survivors growing in temperate zones[].

Edible Uses

None known

Medicinal

The fruits are diuretic[].

The bark is astrigent[].
Kino, a resin obtained from the trunk, is taken internally as an effective treatment for dysentery, working because it is not absorbed at all from the stomach and only very slowly from the intestine, and is thus able to directly treat the lower part of the intestine[]. When mixed with water and swallowed, it is also reputed to have anti-inflammatory properties[].

A flavonoid derivative, naringenin, has been isolated from the fruits[].
The presence of leucoanthocyanin in the bark is probably responsible for its astringency[].

Agroforestry Uses:

The tree is fast-growing and so has been used for reforestation, and is also planted as a windbreak and to provide shade[].
In Australia, the tree is a major source of winter nectar, the honey is highly prized[]. The flowers are also a good source of pollen[].

Other Uses

The leaves yield an essential oil, the main component being 1,8-cineole. The yield of oil is 1.8-2.8%[].
An essential oil is obtained from the leaves. Total quantity of the oil, and its composition, can vary widely from plant to plant, but we have reports that the fresh leaves contain around 0.2 - 0.8% (0.5 - 1.1% dry weight) essential oil. The main components include 1,8-cineole (55% in some forms), pinene, globulol, eudesmol, phellandrene[].

An extract of the plant (this probably refers to the essential oil[]) is used as an ingredient in commercial cosmetic preparations as a skin conditioner[].

The leaves show insecticidal activity, an extract has been used against mosquito with the principal active ingredient p-menthane-3,8-diol[].

A kino resin is obtained from the trunk[]. Kino resins are rich in tannins and are very astringent. They can be used medicinally, in tanning, as well as for preserving and dyeing natural fibres. The resin oozes naturally from wounds in the trunk and can be tapped by making incisions in the bark. At first it is a thick liquid, but soon hardens upon exposure to the air and sun, typically drying to an amber-like material that consists of dark red angular fragments, rarely larger than a pea.

The heartwood is light brown to dark brown; the up to 8cm wide band of sapwood is paler. Texture is moderately coarse, with an interlocked grain; the frequent presence of wavy grain produces an attractive 'fiddleback' grain. The wood is slightly greasy and gum veins are common. It is heavy, hard, strong, very tough and moderately durable. Easy to work, it is widely used for structural purposes, including heavy construction where shock resistance is important, and also for poles, flooring, furniture, veneer, railway sleepers and tool handles[, , ].
The tree is an important fuelwood[].

Propagation

Seed - surface sow late winter/early spring in a sunny position in a greenhouse[, , ]. Species that come from high altitudes appreciate 6 - 8 weeks cold stratification at 2°c[]. Pot up the seedlings into individual pots as soon as the second set of seed leaves has developed, if left longer than this they might not move well. Plant out into their permanent positions in early summer and give them some protection from the cold in their first winter. The seed can also be sown in early summer, the young trees being planted in their final positions in late spring of the following year. The seed has a long viability[]. Seeds can be maintained for several years in hermitic storage at 3°c, with 6 - 10% moisture content[].