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 redolens is a spreading, low-domed shrub usually growing 50 - 200cm tall, but occasionally becoming a tree up to 5 metres tall[]. 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 local use as a food. It has been suggested as a potential commercial seed crop for areas such as Western Australia and as a soil stabilizer and revegetator in arid areas[].

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 - southern Western Australia

Habitat

Found in slightly saline or alkaline loam, clay or clay loam, often with Salmon Gums (Eucalyptus salmonophloia ) or Stocking Gum (Eucalyptus kondinensis ) and frequently around the margins of salt lakes[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Shrub
Height	1.50 m
Pollinators	Insects
Cultivation Status	Cultivated, Wild

Cultivation Details

Acacia redolens is native to the Mediterranean climate of southwestern Western Australia, where it can be found at elevations up to 200 metres. It grows best in areas where the mean maximum temperature of the hottest months can reach 27 - 28°c, and the mean minimum in the coldest month can fall to 5 - 6°c. The plant can experience occasional moderate frosts, down to around -5°c for short periods. Mean annual rainfall can vary from 420 - 475mm, with a variable dry season that can range from 6 - 7 months[].
Requires a sunny position[1293. Succeeds in a range of well-drained soil from sandy loams to clay[]. Tolerant of saline soils[].
A fragrant plant, with the scent of vanilla[].
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[].
Very closely related to Acacia trineura from eastern Australia which has ±straight pods and dark green phyllodes with generally fewer longitudinal nerves of which only 1 - 3 extend to the apical point (many nerves extending to the apex in Acacia redolens[].
Superficially similar to Acacia cyclops which is most readily distinguished by its larger flower-heads, pods and seeds; the seeds with a distinctive encircling red or orange funicle/aril[].
It is also similar to Acacia warramaba[].

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 seedpods are up to 6cm long and 2 - 3.5mm wide, with dark brown, narrowly elliptic-oblong seeds 3.5 - 4mm 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[].

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 species has been utilised in the U.S.A. for median strip planting and for reclamation of degraded sites; it is also growing very well in windy coastal situations under extreme conditions[].
It has been introduced to central Arizona (USA) as shade tree and for soil stabilization in desert areas. It has been experimentally cultivated as a ground cover and for erosion control in desert areas due to its drought, alkaline and cold tolerance[].

Other Uses

None known

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[].