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: Myall

General Information

Acacia acuminata is an evergreen shrub or a small tree that can grow up to 12 metres tall in the west of its range but is generally smaller towards the east[, ]. Often multistemmed, when single-stemmed the bole is generally straight, 30 - 200cm long and 10 - 30cm in diameter[].
The tree produces a high quality timber, though it is generally on the small side. It is harvested from the wild for mainly local use. The tree is also said to be a traditional food source for the native Australians and is also grown as an ornamental, where it can be used as a hedge. It has been proposed as a potential commercial seed crop in Western Australia[, ].

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 - Western Australia, South Australia, New South Wales

Habitat

Often in gently undulating topography, on lateritic gravels or red-brown earths in low semi-arid woodlands and tall shrublands, and in clayey soils on flats and in red sands, often near intermittent streams[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Tree
Height	8.00 m
Growth Rate	Medium
Pollinators	Insects
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Acacia acuminata is a plant of semi-arid, warm temperate to subtropical climates with a mainly winter rainfall. It is found at elevations up to 400 metres. It grows best in areas where annual daytime temperatures are within the range 17 - 28°c, but can tolerate 6 - 38°c[]. When dormant, the plant can survive temperatures falling occasionally to about -5°c, but young growth can be severely damaged at 0°c[]. It prefers a mean annual rainfall in the range 350 - 500mm, but tolerates 300 - 700mm[].
Found in the wild on soils that range from clays to red sand and granitic gravels[]. Succeeds in soils of medium to low fertility[]. Established plants are fairly drought tolerant[]. Prefers a pH in the range 6 - 7, tolerating 5.5 - 7.5[].
The plant can be grown as an ornamental, where it can be used to make a hedge or screen[].
The plant has potential for use as a cultivated edible seed crop. It can produce heavy yields of palatable seeds, but its fruiting behaviour tends to be erratic and possibly related to the timing, frequency and intensity of rainfall[].
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[].
A moderately long-lived but relatively slow growing small tree[].
Plants do not respond well to coppicing[].
This species is the main tree being used as a host in sandalwood (Santalum species) plantaions[].

Edible Uses

Seed - cooked[]. Palatable[]. 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[]. Traditionally, the seeds were ground into a powder and then cooked[]. The very dark brown to brownish black, oblong to almost globose seed is 3 - 6mm 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[].

A gum, resin and the seeds are said to be traditional foods of the Aborigines[].

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 plant has wide-ranging roots and can be used for soil stabilization, especially on sandy sites[]. It can also be used to make a hedge or screen[].

Other Uses

The tree yields a scented wood, which may have potential for use in perfumery[].
This wood possesses a rich colour, varying from violet to crimson, with a very hard, close, lustrous grain. It is said to be very durable, and is reported to be able to last seventy years in the ground as posts[, ]. An aromatic wood with a scent some describe as like violets and others as raspberries; a small ornamental box nearly forty years old still retained its scent, which was apparent on opening the lid[]. It is probable that, when in a fresher condition, the wood possesses a stronger and different scent. It is a valuable wood for turnery and inlay, solid wood products, craftwood, posts (including fencing), and as a speciality timber for quality furniture[, , ].
The wood makes a high quality fuelwood, and is also used to make a high quality charcoal[, ].

Propagation

Seed - best sown as soon as it is ripe in a sunny position in a warm greenhouse[]. Stored seed should be scarified, pre-soaked for 12 hours in warm water and then sown in a warm greenhouse in early spring. The seed germinates in 3 - 4 weeks at 25°c[]. 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[].
Cuttings of half-ripe wood with a heel, mid summer in individual pots in a frame[]. Overwinter in a greenhouse for the first winter and plant out in their permanent positions in late spring or early summer. Fair percentage[].