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Acacia binervata

Two-veined Hickory

Family: Fabaceae Subfamily Mimosoideae

A tree to 15 m tall, which can create a dense canopy.

It is found in a range of habitats, growing in dry to moist sites in sandy, to more enriched, to basalt soils. It can be found in dry and wet sclerophyll woodland and forest, or on the margins of rainforest communities.

It occurs along the east coast, from south-east Queensland through much of coastal New South Wales, to around Narooma.

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).

It is thought that Groups 1 and 2 are more highly evolved than Group 3.

This species is of Group 1: the phyllodes are usually distinctive and aid identification; usually with two distinctive veins, narrowly ovate to narrowly elliptic in shape, straight to slight curved, to around 15 cm long (usually shorted) and to 3 cm wide.

Acacia spp. produce small 5-merous flowers, with 5 very small petals partly-fused into a short tube which sits above a fused calyx. The stamens are the main feature which are produced in high numbers per flower (staminate flowers), surrounding a single style. In this species, inflorescences consist of very small staminate flowers, arranged in globular heads of up to 50, with heads in racemes (or sometimes in panicles) of up to 12; pale yellow, seen in August to November.

The fruit is a pod, to 14 cm long, and to 1.5 cm wide; straight and flat.

In the garden

This plant is popular in cultivation as it is hardy, in most well-watered situations and grows in full sun or part shade.

Frost hardy to -7 C and suitable as a tall hedge or screen plant.

It can be often seen in the wild growing in a copse and so can be grown this way. Very useful shade tree for any garden or landscape with enough space. Often found on sandy to shale soils, so provide adequate drainage.

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 will die in a fire and regenerate from seed. Some species exhibit suckering from basal parts and roots.

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.

binervata – Latin for the two main longitudinal veins (nerves) of the phyllodes. (Note: there is also a NSW species named Acacia binervia which is not morphologically similar but there is potential to get the species names confused).

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

Wattle – Acacias of Australia – Acacia binervata profile page https://apps.lucidcentral.org/wattle/text/entities/acacia_binervata.htm

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

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

By Jeff Howes. Editing and additional text by Dan Clarke.