Acacia obliquinervia

Mountain Hickory Wattle

Family: Fabaceae subfamily Mimosoideae

A medium-sized tree, growing to 15 m high.

It is found in NSW, south from Merriwa in the Hunter Valley, extending south to about Taralga. Then with a disjunction to the ACT where it extends south through the tablelands and coastal hinterland. It grows in Victoria, from the north-east of the state through to Melbourne with records also south of Horsham.

It generally grows in dry to moist sclerophyll forest, often on sandstone.

Australian Wattles at least, can be broadly placed into 1 of 3 recognisable groups:

Group 1: Those that produce juvenile compound-bipinnate leaves and then change to producing adult-phyllodes which are modified-flattened petioles which form the foliage. This is combined with flowers produced in globular balls or heads (or ovoid heads). The heads can be singular in leaf/phyllode axils or arranged in groups.
Group 2: As for Group 1 but flowers are produced in longer rod-like spikes.
Group 3: Those that never produce phyllodes and retain the juvenile compound-bipinnate foliage into adulthood. These always produce flowers in globular balls (which are secondarily arranged into panicle or raceme-like groups in many cases).

This wattle belongs to Group 1.

Phyllodes (modified leaves) are obovate to narrowly oblanceolate, to about 15 cm long and to about 5 cm wide and grey-green in colour.

Flowers are arranged in globular heads, to 8 mm diameter, with up to 30 very small staminate flowers per head, yellow in colour. The heads are arranged in racemes or panicles, in phyllode axils, with up to 16 heads per raceme, occurring from August to December.

Seed pods are straight or slightly curved, to 15 cm long and to 2.5 cm wide.

In the garden

A suitable plant for ornamental foliage.

Hardy in well-drained soils. Needs reasonable moisture to thrive.

Bright yellow flowers standout well against the grey foliage.

Acacias can suffer from a number of pests, including borers, scale, galls and leaf miners. Growing plants suitable to your local environment minimises these occurring.

Propagation

Propagation is easy from scarified seed by covering with boiling water for 24 hours and discarding any seeds still floating on the surface.

Other information

Most wattles regenerate from seed after fire with some species exhibiting suckering from bases or trunks.

Acacia is a highly diverse genus, with over 1500 recognised species (placing it in the top-10 most-diverse plant genera) occurring in most continents except for Europe. Australia has about 970 spp., most of which are endemic. There are also about 10 exotic species. NSW has about 235 recognised species. Some species have become weeds in other states outside of their natural range (e.g., wattles from Western Australia into NSW and vice versa).

Acacia – from Greek Akakia – which refers to an Ancient Greek preparation made from one of the many species; the name of which derives from akis, meaning “thorn” – referring to the thorns of species in Africa.

obliquinervia – refers to the oblique venation of the phyllodes

This species is not considered to be at risk of extinction in the wild.

NSW Flora Online (PlantNET) – Acacia obliquinervia profile page
http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Acacia~obliquinervia

Wattle – Acacias of Australia Online – Acacia obliquinervia fact sheet https://apps.lucidcentral.org/wattle/text/entities/acacia_obliquinervia.htm

Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4^th edition. New Holland Publishers, Pty. Ltd. Australia.

January 29, 2021