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 murrayana is a single or multistemmed evergreen shrub or a tree with a spreading canopy; it usually grows up to 5 metres tall, sometimes reaching 8 metres. The plant can be single or multiple-stemmed from the base, sometimes producing suckers and forming colonies[, ]. Although it produces true leaves as a seedling, like 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 a traditional food for the native Australians and has potential as a cultivated and also wild-harvested food. The wood is a very good fuel. The tree flowers freely and can be grown as an ornamental.
The plant's capacity to regenerate vigorously both from seed and vegetatively suggests that it has a potential to become a weed on favourable sites[].

Known Hazards

The seed of many Acacia species, including this one, is edible and highly nutritious, and can be eaten safely as a fairly major part of the diet. Not all species are edible, however, and some can contain moderate levels of toxins[]. Especially when harvesting from the wild, especial care should be taken to ensure correct identification of any plants harvested for food[].
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 - mainly in the central arid belt from Western Australia, South Australia, Northern Territory, New South Wales and Queensland

Habitat

A component of woodland and low woodland in the higher rainfall areas, more commonly in tall open-shrubland and hummock grassland in more arid regions, growing in sand on dunes, plains or along streams; at elevations up to 700 metres[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Shrub
Height	5.00 m
Growth Rate	Fast
Pollinators	Insects
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Acacia murrayana is a plant of arid and semi-arid regions in the warm temperate, subtropical and tropical zones of central Australia, where it is found at elevations up to 700 metres. It grows best in areas where annual daytime temperatures are within the range 12 - 34°c, but can tolerate 5 - 42°c[]. When dormant, selected provenances of the plant can survive temperatures down to about -10°c, but young growth is more tender and can be severely damaged at -1°c[]. It prefers a mean annual rainfall in the range 200 - 400mm, but tolerates 100 - 500mm[].
Requires a sunny position and a well-drained soil[]. Succeeds in a range of soils from sands to clays and is very tolerant of low fertility[]. Prefers a pH in the range 5.5 - 7.5, tolerating 4.5 - 8.5[]. Established plants are drought tolerant[].
A fast-growing plant when young, but relatively short-lived, usually senescing when around 15 - 25 years old[].
The plant recovers well following fire - both by producing a flush of germinating seedlings and also by resprouting from the base[].
The seeds of most acacia species can be quickly and efficiently harvested at full maturity without the need for any specialised equipment. Small seed-bearing branches can be cut and beaten on sheets, or bushes can be beaten or shaken directly onto large sheets[].
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[].
Acacia murrayana, together with Acacia gelasina, Acacia pachyacra, Acacia praelongata and Acacia subrigida comprise the ‘Acacia murrayana group’ of closely related species. This group of species is not far removed from the ‘Acacia victoriae ’ and ‘Acacia juncifolia ’ groups[].
Some forms of this species may resemble Acacia dietrichiana[].

Edible Uses

Seed - cooked[, , , ]. It can be eaten in the same ways as other small legume seeds and is also ground into a powder then used as a flavouring in desserts or as a nutritious supplement to pastries and breads[]. The pods are up to 90mm long, 8 - 12mm wide, with ovate, black seeds 4 - 5.5mm long[].
Acacia seeds are highly nutritious and contain around 26% protein, 26% available carbohydrate, 32% fibre and 9% fat. The fat content is higher than most legumes with the aril providing the bulk of fatty acids present. These fatty acids are largely unsaturated. The energy content is high in all species tested, averaging 1480 ±270 kJ per 100g. The seeds are low glycaemic index foods - the starch is digested and absorbed very slowly, producing a small, but sustained rise in blood glucose and so delaying the onset of exhaustion in prolonged exercise[].

The ground seed can be used to produce a high quality, caffeine-free coffee-like beverage[].

The plant possibly produces an edible gum[].

Medicinal

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 can provide low shelter, it can be used as an ornamental and is a pollen source for bees[].

Other Uses

The wood is of small dimensions, but can be used for posts and small turnery[].
The wood is highly suitable for fuel, and for making charcoal[].

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[].