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[
Racosperma argyrodendron (Domin) Pedley
Common Name: Black Gidyea
Acacia argyrodendron is an evergreen tree that usually grows 8 - 15 metres tall, but can reach 25 metres. The bole is straight and cylindrical[
]. 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 of its wod. It can be used in soil stabilization projects and is grown as an ornamental.
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.
Australia - central Queensland
Grows mostly in dark cracking clay, either alone or, on the southern and eastern edge of its range, with Brigalow (Acacia harpophylla); at elevations from 150 - 350 metres[
|Other Uses Rating||
|Cultivation Status||Ornamental, Wild
Acacia argyrodendron is a plant of the semi-arid, subtropical to tropical zones of eastern Australia, where it is found at elevations up to 350 metres. It grows best in areas where annual daytime temperatures are within the range 22 - 32°c, but can tolerate 10 - 40°c[
]. It prefers a mean annual rainfall in the range 450 - 550mm, but tolerates 350 - 650mm, tolerating a dry period of 4 - 6 months[
Requires a sunny position[
]. Grows best in a light, well-drained soil, but can tolerate heavy soils and occasional waterlogging of the soil[
]. Succeeds in soils of low fertility[
]. Established plants are drought tolerant[
]. Prefers a pH in the range 6.5 - 8, tolerating 5 - 9[
A fairly slow-growing plant, though it is generally long-lived.
The tree generally responds well to coppicing, and can produce root suckers.
Sometimes grown as an ornamental[
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.
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[
The tree can be used for shelter and to provide erosion control[
The wood is heavy, hard and strong. It can be utilized as posts, poles, and rail material[
The wood is a good fuel and can be used to make a good quality charcoal.
The 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.
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[
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