Masses of seed pods are produced in the months following the flowers and may persist on the tree long after the seeds have been shed.Evidence of browsing by deer or cattle on a small blackwood seedlingWith Ken Slee
One of the characteristic trees of sambar country, this ‘wattle’ is a tree that every aspiring sambar hunter needs to be able to recognise – it is a favoured browse plant, is frequently a target of rubbing by stags and isn’t a bad shelter tree as well, so it ticks most boxes as far as the deer are concerned.
Despite similar names, the blackwood is very different from the related black wattle (A. mearnsii) that has featured previously in this column. The blackwood is a small to medium sized tree that produces classic ‘wattle’ flowers and large seed pods, just like the black wattle, but that is about where the similarities end.
· Blackwoods are a relatively slow-growing and long-lived species whereas black wattles adopt a ‘grow fast, seed and die young’ strategy, mostly completing their life cycle in 20 years after a fire.
· Black wattles die young as a result of attack by wood boring grubs and evidence of this is usually obvious because of oozing sap, borer holes and damaged bark. Blackwoods by comparison seem to be immune to such damage.
· Although blackwoods will germinate from seed after a bushfire, their usual response is to push up numerous suckers from their roots to form thickets over a small area. Black wattles on the other hand often germinate in millions after a fire and blanket whole hillsides.
Blackwoods have leaves that are shaped like those of gum trees while those of the black wattle are feathery.
In most of Victoria’s sambar country blackwoods grow as medium-sized, spreading trees, perhaps six to 12 metres tall. However, in favourable locations such as in a moist gully or a high rainfall area they can be considerably taller. As the name suggests, the heartwood of this tree is dark, attractive and may show ‘fiddleback’ with the result that timber from bigger examples is used in such things as cabinet, furniture and gunstock making.
The foliage of the mature blackwood is typically dense and provides good shelter. Leaves are dark green and have prominent veins running along their length. In an open forest a pruned line above the ground is often very conspicuous, a result of browsing by wallabies, cattle or deer. Suckers following bushfire are also likely to show evidence of browsing with stems and leaves nipped off. Leaves lost from trees are probably also eaten off the ground by deer. Blackwood seedlings have feathery foliage before the adult leaves develop.
Flowers are produced in spring and are pale cream in colour. Seed pods are pale brown, up to 12 centimetres long and usually occur in twisted masses. Seeds are about 4 millimetres long, black and have a tough coat that allows them to survive for years in the soil before they germinate.