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 leucoclada (Tindale) Pedley
Acacia leucoclada is sometimes a shrub growing around 2.5 - 4 metres tall, but more commonly becoming a tree; it usually grows up to 10 metres tall, reaching 20 metres in favoured situations, especially in the north of its range (subspecies argentifolia)[
]. The single trunk often divides into two main stems at around 2 - 7 metres tall, the straight boles being around 13 - 45cm in diameter. In shady situations the plants develop a rather spindly growth habit (with stems straight and erect), often freely suckering and forming pure stands[
]. Unlike most Australian species of Acacia, this species retains its true foliage into maturity and does not produce phyllodes[
Acacia leucoclada is regarded as having good prospects as a crop plant for high volume wood production[
]. It is also grown as a pioneer species for establishing native woodland and can be used in shelterbelts and in soil stabilization projects.
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 - New South Wales, southeastern Queensland
Open forest, usually in association with eucalypts and Callitris species, in poor sandy or gravelly soils, often on basalt or acid granite
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Acacia leucoclada grows in semi-arid to sub-humid areas of the temperate to subtropical zone of eastern Australia where it can be found at elevations up to 780 metres. It grows best in areas where the mean maximum temperature of the hottest months can reach 29 - 34Â°c, and the mean minimum in the coldest month can fall to 0 - 3Â°c. The plant can often experience moderate frosts, down to around -5Â°c for short periods. Mean annual rainfall can vary from 250 - 875mm, with a variable dry season that can range from 0 - 6 months[
Requires a sunny position for best growth, often found in shady positions but then usually a spindly shrub[
A fast-growing tree when young[, probably living for several decades1301].
In one trial, in an area with around 600mm annual rainfall, this species showed good form, attained 5.6 metres in height and 7.2cm in diameter, at the age of 30 months[
The plant can sucker freely, but is unlikely to respond well to coppicing[
]. Prefers a well-drained soil, succeeding in light to moderately heavy conditions[
]. At least some forms have shown themselves to be drought-tolerant[
This species has in the past been confused with Acacia dealbata, but differs in various aspects, including its more open growth habit[
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[
A useful windbreak species , it also provides excellent gully erosion control on account of its fast growth rate, vigorous suckering habit and propensity to form thickets[
The tree is a natural pioneer, invading cleared farmland within its native range. It is an ideal 'nurse crop' for use with slow growing eucalypts species or other long-lived species in mixed woodlots[1301.
The small core of heartwood is pale brown; the sapwood is white. It is a potential source of small round timbers for use as posts, poles or rails[
]. Although this species produces pulp yields within the range of commercial pulpwoods its level of brightness (upon bleaching) is below standard[
The wood is likely to make a good fuel and a good charcoal[
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[