Common Name: Red River Gum

General Information

Eucalyptus camaldulensis is an evergreen tree with a short, thick bole and a large, spreading crown[]. It commonly grows to about 20 metres tall, though occasional specimens can reach 50 metres[]. When grown in plantations, the tree has an erect, lightly branched crown with a bole that can be unbranched for up to 20 metres and 100 - 200cm in diameter[, ].
A very important timber crop, the tree also yields an essential oil and has various medicinal applications. This species is regarded as one of the most widely planted eucalypts in the world with more than 500,000 hectares planted[]. It is planted in Europe, especially in Italy, as a timber crop, for soil stabilization and as an anti-malarial measure[]. Its graceful form is attractive and so it is often planted in avenues and gardens[].

Known Hazards

None known

Botanical References

, ,

Range

Australia - in all mainland states

Habitat

Sandy to heavy soils[], usually along the banks of streams[]. A dominant species in grassy woodland or forest on deep rich alluvial soils adjacent to large permanent water bodies[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Tree
Height	30.00 m
Growth Rate	Fast
Pollinators	Bees, Insects
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Eucalyptus camaldulensis is a plant of low to moderate elevations in tropical, subtropical and warm temperate areas where it is found at elevations from sea level to 1,500 metres[]. It grows in areas where the mean annual precipitation is in the range of 250 - 2,500mm and an annual temperature range of 3 - 22°c minimum to 21 - 40°c maximum[, ]. A fairly frost resistant species, plants from some provenances are known to survive temperatures down to at least -7°c in Australian gardens[, ]. The tree is reported to grow in areas with only 200mm rainfall, but the lower limit for commercial plantations is 400mm[]. The dry season can last 4 - 8 months or more and may be severe, though for the tree to still flourish in such conditions it needs access to ground water[, ].
Prefers a sunny position in a moderately fertile well-drained moisture retentive circum-neutral soil[]. Succeeds in most soils[], growing well in heavy clays and also tolerating poor and dry soils, especially those low in mineral elements[, ]. Some provenances tolerate many different soil conditions such as high calcium, high salt and periodic water-logging[]. The plant prefers a pH in the range 5 - 7, tolerating 4.5 - 8[]. A drought resistant tree once established[, ], it is slightly salt tolerant[], and can also withstand periodic inundation[].
A very fast growing tree[]. On the very best of sites annual growth rates of 4 - 7 metres have been recorded with 4 - 6cm increases in diameter; but on drier sites annual growth of around 120cm is more common[].
Some provenances coppice well for six or more rotations, on good sites, plantations are managed on coppice rotations of 7 - 10 years[].
According to NAS (1980a), annual wood yields are around 20 - 25 cubic metres per hectare in Argentina, around 30 cubic metres from Israel, 17 - 20 cubic metres from Turkey in the first rotation, rising to 25 - 30 cubic metres in subsequent coppice rotations[]. On poor arid sites yields are only 2 - 11 cubic metres on 14 or 15 year rotations[].
Trees can start flowering when less than 2 years old and in suitable climates will flower and produce seed all year round[].
Eucalyptus 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[].
Trees are liable to shed branches, especially in hot weather[].
This is said to be the most widely distributed eucalyptus tree in Australia, ranging over 23° of latitude. It is found in most of arid and semiarid Australia but not the humid eastern and south-western coasts[, ].
Whilst most Eucalyptus 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[].
Plants are shallow-rooting and, especially in windy areas, should be planted out into their permanent positions when small to ensure that they do not suffer from wind-rock[]. They strongly resent root disturbance and should be container grown before planting out into their permanent position[].
Survivalists in Australia and elsewhere might learn how the aborigines obtained water from the superficial roots, usually those around 3cm in diameter. The roots were excavated or lifted to the soil surface. Then the root was cut into segments about 45cm long, debarked, held vertically, and blown into, the water then draining into the receptacle provided[].

Edible Uses

Seed[]. No further details are given but the seed is very small, not much bigger than a speck of dust[].

Medicinal

Eucalyptus leaves are a traditional Aboriginal herbal remedy. A leaf infusion is used to bathe the head in case ofcolds or fevers[].
The essential oil found in the leaves is a powerful antiseptic and is used all over the world for relieving coughs and colds, sore throats and other infections[]. The essential oil is a common ingredient in many over-the-counter cold remedies[].

The plant is an aromatic, astringent, tonic herb that sticks to the teeth and turns the saliva red[]. The report says that the leaves, essential oil and kino resin are used[], but does not specify which properties apply to the different parts of the plant[]. The leaves and the oil will have very similar properties, the oil being much stronger in its effect since it is distilled from the leaves[]. Detailed below is how the kino -resin and oil are commonly used in other species[].

The essential oil obtained from various species of eucalyptus is a very powerful antiseptic, especially when it is old, because ozone is formed in it on exposure to air. It has a decided disinfectant action, destroying the lower forms of life[]. The oil can be used externally, applied to cuts, skin infections etc; its vapours can also be inhaled for treating blocked nasal passages; it can be gargled for sore throat; and can also be taken internally for a wide range of complaints[]. Some caution is advised, however, because like all essential oils, it can have a deleterious effect on the body in larger doses[].

A kino- resin is exuded from the tree[, ]. It can also be obtained from the tree by making incisions in the trunk[, ]. This resin contains tannin and is powerfully astringent, it is used internally in the treatment of diarrhoea and bladder inflammation[, , , ], externally it is applied to cuts etc[, ].

Agroforestry Uses:

The tree is widely planted for shade and shelter[]. In Sudan it is planted to protect crops from blowing sand[].
With its light crown, the tree is well suited for growing in arable fields. Intercropping maize with trees planted at 5 x 5 metres gives satisfactory yields[].
A fast growing tree with wide-ranging roots, it can be planted in soil stabilization schemes. The tree develops a strong taproot and the lateral roots can attain lengths 2.5 times the height of the tree, making it particularly effective for erosion control[].
The tree can also be planted in marshy land where it will help in draining the land, thereby destroying a potential breeding site for mosquitoes[]. It is planted in S. Italy for this purpose.
The flowers are a good source of nectar and pollen for bees[].

Other Uses

A gum is obtained from the trunk. It is used medicinally, as a dye and in tanning[, , ].

The leaves, especially of plants grown in tropical climates, contain 0.1 - 0.4% essential oil, 77% of which is cineol There is some cuminal, phellandrene, aromadendren (or aromadendral), and some valerylaldehyde, geraniol, cymene, and phellandral[, ]. The oil is much used medicinally, as well as in perfumes, soaps, detergents etc[]. It is also used as a pesticide[].

The leaves contain 5 - 11% tannin. The kino contains 45% kinotannic acid as well as kino red, a glycoside, catechol, and pyrocatechol[]. The leaves and fruits test positive for flavonoids and sterols[]. The bark contains 2.5 - 16% tannin, the wood 2 - 14%, and the kino 46.2 - 76.7%[].

The smoke from burning leaves helps to repel insects[].

The peeled twigs are used as chewing sticks in order to clean the teeth and maintain oral hygiene[]. The bark contains compounds with antimicrobial activity and is best left on the stem when chewing[].

The heartwood is reddish with fine grains, turning reddish-brown upon exposure; it is clearly demarcated from the 50 - 75mm wide band of paler sapwood. The grain is interlocked, straight or wavy, often producing an attractive figure, texture is moderately coarse. When grown in plantations, however, it often has unfavourable characteristics such as growth stresses, shrinkage on drying, collapse, spiral grain and starch in the sapwood. The wood is moderately heavy, very strong, resistant to termites, considered to be one of the most durable woods in the world, extraordinarily hard yet easy to saw. Splitting may occur due to the release of growth stresses; it is difficult to work and should be pre-bored before nailing, but gluing properties are good and the wood polishes well. It is suitable for steam-bending[, , , ]. It is widely used in Australia for strong durable construction, interior finish, flooring, cabinetry, furniture, fence posts, cross-ties, sometimes pulpwood[]. Australian aborigines made canoes from the bark[].
The firewood is suitable for industrial use in brick kilns but is not preferred for domestic use because it is too smoky and burns too fast. However, it makes good-quality charcoal and is used in several countries for the large-scale production of charcoal for the iron and steel industry[].

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[].