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 stenophylla is a somewhat bushy tree with a spreading, rounded crown and pendulous branches; it can growi 4 - 20 metres tall. Sometimes a single-stemmed plant, the bole often divides into several stems about 100cm above the ground; single stems can be 35 - 60cm in diameter. The plant has a tendency to produce suckers[, ]. 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 tree is harvested from the wild for local use as a food and source of materials. It produces a good quality wood that can be used to make furniture. It can be planted to form a windbreak, can be used in soil reclamation projects and is also grown as an ornamental.

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 - all mainland States

Habitat

Very widely distributed in inland arid areas, growing in heavy soils along watercourses subject to periodic flooding where it frequently forms monospecific stands; at elevations up to 625 metres[].

Properties

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

Cultivation Details

Acacia stenophylla is a plant of inland arid and sub-arid regions of the warm temperate to tropical zones, growing throughout Australia, where it is found at elevations up to 625 metres. It grows best in areas where annual daytime temperatures are within the range 18 - 32°c, but can tolerate 5 - 42°c[]. When dormant, the plant can survive temperatures down to about -10°c, but young growth is more tender can be severely damaged at -1°c[]. It prefers a mean annual rainfall in the range 200 - 600mm, but tolerates 100 - 800mm[].
Requires a sunny position[]. Grows best in a well-drained, medium to heavy-textured soil of moderate to low fertility, tolerating very saline soils[]. Plants can withstand seasonal inundation of the soil[]. Prefers a pH in the range 7 - 8, tolerating 6.5 - 8.5[].
A moderately fast-growing tree, able to increase height by 80 - 170cm per year when young[].
The tree coppices and produces root suckers following damage by fire[].
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[].

Edible Uses

Seeds - 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 woody seedpods can be 10 - 26 cm long and 6 - 12mm wide, with dark brown, broadly elliptic to oblong-elliptic seeds 7 - 9mm[]
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[].

Young seedpods - cooked[].

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 is a good windbreak, and it can be used for rehabilitating mine dumps[].

Other Uses

The heartwood is dark, reddish-brown to almost black and beautifully marked. The wood is very hard, heavy, close-grained, and takes a fine polish. It planes excellently, showing a very smooth surface. It can be used for furniture, fence posts etc[, , ].
The wood is an excellent 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[].