Acacia pubescens, also called downy wattle, is a type of wattle plant found in the Sydney Basin in eastern New South Wales. It is a vulnerable species because much of its home has been lost as the city of Sydney has grown. Like all wattles, it has special leaf stems called compound (pinnate) leaves.
Acacia pubescens grows as a small bush or tree, from 1 to 5m (3 to 20ft) tall. Its bark is smooth and grey-brown. The branches may hang down a little. The downy wattle has leaf-like parts called phyllodes. These are compound (pinnate) and are 1.5–6.5cm (0.59–2.56in) long. They have 3 to 12 pairs of smaller leaf parts called pinnae, each 0.5–2.5cm (0.20–0.98in) long. Each pinna has 5 to 20 pairs of even smaller parts called "pinnules".
The plant has round yellow flowers that grow in groups called racemes. The flowers bloom from late winter to spring (August to October), with the most flowers in September. Each flower group has 12 to 20 small flowers. After flowering, seed pods grow that are 3–7cm (1.2–2.8in) long. These pods ripen from October to December.
Taxonomy
The downy wattle was first described by French botanist Étienne Pierre Ventenat in 1803. It was first called Mimosa pubescens. Later, Robert Brown gave it the name Acacia pubescens in 1813. The name "pubescens" means "hairy," which refers to the hairy stems of the plant. It is also called hairy-stemmed wattle.
The plant belongs to a group of wattles with "bipinnate" leaves. Some scientists have studied its DNA and found that this group is not all closely related. The downy wattle can sometimes crossbreed with other wattles like the Cootamundra wattle and West Wyalong wattle.
Where it grows
Acacia pubescens only grows in New South Wales, mainly in the Sydney Basin. It is found in small groups from Bardwell Valley to Oakdale and Mountain Lagoon. Most plants are near Bankstown, Fairfield, Rookwood, and Pitt Town in Sydney. Much of its home has been lost to city growth, so it is now listed as a vulnerable species. It grows in clay soils and open forests with other plants like grey box trees, ironbark trees, honeymyrtle, and blackthorn.
Ecology
These plants can live up to 50 years in the wild. They can grow new shoots from their roots after bushfires.
References
12NSW National Parks and Wildlife Service Sydney (February 2003). "2. Legislative Context". National recovery plan for the Downy Wattle (Acacia pubescens). Environment Australia. Retrieved 7 May 2012.
↑Brown, Gillian K.; Ariati, Siti R.; Murphy, Daniel J.; Miller, Joseph T. H.; Ladiges, Pauline Y. (1991). "Bipinnate acacias (Acacia subg. Phyllodineae sect. Botrycephalae) of eastern Australia are polyphyletic based on DNA sequence data". Australian Systematic Botany. 19 (4): 315–26. doi:10.1071/SB05039.
