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: Southern Ironwood

General Information

Acacia estrophiolata is a graceful tree developing pendulous branches as it ages; it can grow 4 - 16 metres tall. The bole can be up to 45cm in diameter[, ]. 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 tree is harvested from the wild for local use as a food, medicine and source of materials.

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 - South Australia, Northern Territory, Western Australia

Habitat

Grows commonly on sandy alluvial flats as scattered trees, but also in tall open shrubland and open woodland[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Tree
Height	10.00 m
Pollinators	Insects
Cultivation Status	Wild

Cultivation Details

It is mainly found to the southern arid part of the Northern Territory, under rainfalls of 220-350 mm without a concentration of rain in a single season, particularly around Alice Springs and in the mountain ranges at the border of the Western and Southern states. It occurs in the Everard and Musgrave ranges in the northernmost parts of South Australia and it may withstand 8-10 days of frost a year[].
Requires a sunny position[]. Prefers a sandy, well-drained soil[].
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[].
This species is closely related to Acacia excelsa[].
There are obvious morphological differences between young and mature plants of this species. The young plants have rigid branchlets and short, straight, patent to erect phyllodes which are normally in nodose clusters; on mature plants the ultimate branchlets are lax and pendulous and the phyllodes are longer and not clustered[].

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[]. Pods flat, breaking readily at constrictions between seeds, to 10 cm long, 5–7 mm wide, firmly chartaceous, reticulate, narrowly winged. Seeds longitudinal, oblong-elliptic, c. 5.5 mm long, dull, brown, exarillate[].
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[].

Medicinal

Bark from branches, root bark and gum used traditionally by N.T. aborigines for treating various skin disorders, upper respiratory tract infections and gastro-intestinal discomfort[].

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[].

Other Uses

The wood is hard and heavy with a thin, whitish sap wood and dark coloured heart. The wood is strong and sufficiently long-lasting to serve as fence post[]. It was used traditionally to make implements and artifacts[].

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[].