Classification of the genus Acacia (in the wider sense) has been subject to considerable debate. It is generally agreed that there are valid reasons for breaking it up into several distinct genera, but there has been disagreement over the way this should be done. As of 2017, it is widely (but not completely) accepted that the section that includes the majority of the Australian species (including this one) should retain the name Acacia, whilst other sections of the genus should be transferred to the genera Acaciella, Mariosousa, Senegalia and Vachellia[].

Common Name:

General Information

Acacia salicina is an evergreen shrub or a tree with drooping branches; it usually grows from 2 - 13 metres tall, occasionally reaching 20 metres. The plant usually develops a well-defined main stem, which can be 30 - 45cm in diameter; it often suckers and can form thickets[, ]. Although it produces true leaves as a seedling, llike most members of this section of the genus, the mature plant does not have true leaves but has leaf-like flattened stems called phyllodes[].
The plant is harvested from the wild for its good quality wood, which can be used to make furniture. It is used in soil stabilization and reclamation projects and is also sometimes grown as an ornamental.

Known Hazards

The leaves contain large amounts of tannin and have been suspected of poisoning hungry cattle[].
Especially in times of drought, many Acacia species can concentrate high levels of the toxin Hydrogen cyanide in their foliage, making them dangerous for herbivores to eat.

Botanical References

Range

Australia - Victoria, New South Wales, Queensland, South Australia, Northern Territory

Habitat

Woodland and open-woodland, mostly along water courses and on floodplains, in soils ranging from sands to heavy clays; at elevations up to 2,000 metres[].

Properties

Medicinal Rating
Other Uses Rating
Habit	Evergreen Tree
Height	10.00 m
Growth Rate	Medium
Pollinators	Insects
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Acacia salicina is a plant of the warm temperate to the tropical zone, often in semi-arid areas. It can be found at elevations up to 2,000 metres. It grows best in areas where annual daytime temperatures are within the range 24 - 30°c, but can tolerate 6 - 36°c[]. When dormant, the plant can survive temperatures down to about -2°c, but young growth is more tender can be severely damaged at -1°c[]. It prefers a mean annual rainfall in the range 400 - 600mm, but tolerates 300 - 700mm[]. It experiences a dry season ranging from 4 - 8 months in most of its range, but in some regions it can be longer[].
Requires a sunny position. Requires a well-drained soil, preferably of medium to heavy texture, but also growing in sands[, ]. Tolerant of very saline soils[]. Prefers a pH in the range 6 - 8, tolerating 5 - 8.5[]. Established plants are drought tolerant[].
A relatively fast-growing tree. Increasing in height by about 1 - 2 metres per year[].
Plants coppice well when young, and also produce root suckers[].
The drooping habit and attractive foliage makes this a desirable species for amenity planting[].
This species has a symbiotic relationship with certain soil bacteria; these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[].

Edible Uses

None known

Medicinal

The pods are rich in saponins[375[.

The bark of all Acacia species contains greater or lesser quantities of tannins and are astringent. Astringents are often used medicinally - taken internally, for example. they are used in the treatment of diarrhoea and dysentery, and can also be helpful in cases of internal bleeding. Applied externally, often as a wash, they are used to treat wounds and other skin problems, haemorrhoids, perspiring feet, some eye problems, as a mouth wash etc[, ].
Many Acacia trees also yield greater or lesser quantities of a gum from the trunk and stems. This is sometimes taken internally in the treatment of diarrhoea and haemorrhoids[].

Agroforestry Uses:

The tree provides shade, shelter, erosion control, and can also be used as a windbreak[].
The tree suckers freely and can be used to stabilise sandy areas and steep banks, and also to control erosion along stream banks[].
The plant is used for mine-site rehabilitation in parts of its natural range[].

Other Uses

A gum is obtained from the trunk and branches[].

The thick, fleshy pods are rich in saponins and produce a froth when agitated in water[]. Saponins often have medicinal applications and can also be used as a soap substitute[].

The bark yields an excellent quality tannin[]. Bark harvested for its tannins should only be taken from mature stems, and only when the sap is rising at the beginning of the growing season - which is when the tannin content is highest and the bark is most easily removed from the wood[].
The rich-brown heartwood is close-grained, tough, moderately heavy and takes a high polish. Nicely marked, it can be used for quality furniture, and was used traditionally for making boomerangs[, , ]. The wood has a rough grain showing that a smooth surface can only be obtained with difficulty, but it is reported as presenting a rich appearance when properly handled[].
The wood should make a satisfactory fuel[].

Propagation

Seed - best sown as soon as it is ripe in a sunny position in a warm greenhouse[].The dried seed of most, if not all, members of this genus has a hard seedcoat and may benefit from scarification before sowing to speed up germination. This can usually be done by pouring a small amount of nearly boiling water on the seeds (being careful not to cook them!) and then soaking them for 12 - 24 hours in warm water. By this time they should have imbibed moisture and swollen - if they have not, then carefully make a nick in the seedcoat (being careful not to damage the embryo) and soak for a further 12 hours before sowing. Sow the seed in Spring in a greenhouse. As soon as the seedlings are large enough to handle, prick them out into individual pots and grow them on in a sunny position in the greenhouse for their first winter. Plant them out in late spring or early summer, after the last expected frosts, and consider giving them some protection from the cold for their first winter outdoors.
Acacia seeds that have matured fully on the bush and have been properly dried have a hard seed coat and can be stored in closed containers without deterioration for 5 - 10 years or more in dry conditions at ambient temperatures. It is best to remove the aril, which attracts weevils and can lead to moulds forming. The arils are easilyremoved by placing the seeds in water and rubbing them between the hands, then drying the seeds and winnowing them[].