Acacia ligulata

Sandhill wattle
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Fabales
Family: Fabaceae
Subfamily: Caesalpinioideae
Clade: Mimosoid clade
Genus: Acacia
Species:
A. ligulata
Binomial name
Acacia ligulata
Occurrence data from AVH
Synonyms
  • Acacia ligulata A.Cunn. ex Benth. var. ligulata
  • Acacia pallidiramosa Maiden & Blakely
  • Racosperma ligulatum (Benth.) Pedley
  • Acacia bivenosa subsp. wayi auct. non (Maiden) Pedley Austrobaileya 1(3): 272, p.p.
  • Acacia salicina auct. non Lindl.: Bentham, G. (5 October 1864) p.p.
  • Acacia salicina auct. non Lindl.: Maiden, J.H. (June 1910), The Forest Flora of New South Wales 4(39) p.p.

Acacia ligulata is a flowering plant in the family Fabaceae. It is a dense, rounded shrub with bright yellow flower heads and is widespread in all states of mainland Australia. Its common names include sandhill wattle, umbrella bush, marpoo, dune wattle, small coobah, wirra, and watarrka (also spelt watarka).

Description

Acacia ligulata grows as an erect or spreading shrub, 2–4 m (6 ft 7 in – 13 ft 1 in) tall and 3 metres across, sometimes dome-shaped, often branching from the ground. The bark is often grooved at the base, but is otherwise smooth. Its branchlets are angular with yellowish ribs, often with hair.

The phyllodes, appearing like leaves, are light to blue green, usually linear-oblong, slightly curved, 30–100 mm (1.2–3.9 in) long and 4–10 mm (0.16–0.39 in) wide, thick, hairless and wrinkled during dry periods. They have a prominent yellowish mid-vein, the lateral veins not apparent. The tip of the phyllode is blunt with a small, hard, downward pointing tip.. Two to four glands are found below the centre of the phyllode and near the tip.

The flowers are borne in two to five spherical heads in racemes 3–20 mm (0.12–0.79 in) long on peduncles 2–10 mm (0.079–0.394 in) long, each head 5–6 mm (0.20–0.24 in) in diameter, with 19 to 24 deep golden yellow flowers.

The seed pods, legumes, are light brown and curved, 50–100 mm (2.0–3.9 in) long and 5–10 mm (0.20–0.39 in) wide, constricted between the seeds and breaking easily into one-seeded segments. The stalk of the seed pod is orange to red. The seeds appear black and oval shaped, normally 4–6 mm (0.16–0.24 in) long, shiny brown with a yellow-orange or red aril.

Taxonomy and naming

Acacia ligulata belongs to the A. bivenosa group of 12 species. Previously considered a variety of A. salicina, differing by its rigid branches, undivided crown, and seed pod characteristics. Earlier literature mentions A. williamsonii as a synonym, other literature places the species in the family Mimosaceae.

The specific epithet (ligulata) refers to the shape of the phyllodes meaning 'strap-like' or 'with a small tongue' in Latin.

Common names include sandhill wattle, umbrella bush, marpoo, dune wattle, small coobah, wirra, and watarrka. The latter name (pronounced what-ARR-kah) is the Luritja word for the species, and gives its name to the Aboriginal (Luritja and Arrernte) name for Kings Canyon, as well as the Watarrka National Park, in the Northern Territory.

Distribution and habitat

Acacia ligulata is one of the most widespread species of Acacia in Australia, common to central and southern Australia, mostly south of the Tropic of Capricorn in arid areas.

Charles Sturt called the habitat ‘stupendous and almost insurmountable sand-ridges of a fiery red’. This area of north-west New South Wales, the Sand Plain Mulga Shrublands, supports an open cover of shrubs and tussock grasses.

This species of wattle is found on sand dunes, the fringes of salt lakes and on floodplains, in mulga and bluebush communities, in woodlands, in mallee communities.

Ecology

Sandhill wattle grows in dense shrub communities on sand dunes, otherwise singly scattered. Fast-growing, it stabilises sand dunes and regenerates quickly after disturbance, such as overgrazing. It is known for potential weediness due to rapid regrowth.

It is found in the hottest and driest climates of Australia with rainfall of less than 200mm and survives light frost. It is an indicative species in sand plain mulga shrublands and was used in an emissions bioassay at Olympic Dam.

Its roots are host to witchetty grub and food for the larvae of the butterfly Nacaduba biocellata. The phyllodes are eaten by cattle and often defoliated by rabbits around the lower part of the plant. Kangaroos and livestock use the plants as shelter. Herbivores grazing on the seedlings can severely limit regeneration.

Reproduction and dispersal

A. ligulata seeds

Acacia ligulata flowers during May to November, depending on the region, odd flowers occurring throughout the year. Seeds are produced between November and January. They have diaspores with fleshy appendages indicating dispersal by birds, including the red wattlebird, and ants (myrmecochory). Ants can transport the seeds up to 180m and disperse it within an area of 3000 m2 around their nest.

Uses

Acacia ligulata is used as a hedge and windbreak, to stabilise sandy areas, for revegetation and erosion control, also in areas with salinity or alkaline conditions. It can be grown from cuttings and has been used as emergency stock fodder.

Indigenous Australians have used the plant by mixing its ashes with the dried and powdered leaves of Duboisia hopwoodii to prepare a stimulant chewing mixture (pituri) for trading. Gum produced by this species was used for consumption, and the seeds were roasted and ground to make damper. Leaves and bark were used for medicinal purposes, to treat colds, chest infections, and general illnesses.

See also

References

  1. 1 2 "Acacia ligulata". Australian Plant Census. Retrieved 22 June 2025.
  2. ↑ Kutsche, Frank; Lay, Brendan; Croft, Tim; Kellermann, Jurgen (2013). Plants of Outback South Australia. Adelaide: State Herbarium of South Australia. p. 45. ISBN 9781922027603.
  3. 1 2 3 4 5 Harden, G. J.. (2002). Flora of New South Wales.Vol.2. Sydney, Australia: University of New South Wales Press Ltd. p. 450.
  4. 1 2 3 Rotherham, E. R., Briggs, B. G., Blaxell, D. F., & Carolin, R. C. (1975). Australian Flora in colour – Flowers and plants of New South Wales and southern Queensland. Sydney, Australia: A. H. & A. W. Reed Pty Ltd. p. 150.
  5. 1 2 3 4 5 6 7 8 9 10 Cunningham, G. M., Mulham, W. E., Milthorpe, P. L., & Leigh, J. H. (1992). Plants of western New South Wales. Melbourne & Sydney, Australia: Inkata Press. p. 365.
  6. 1 2 3 4 5 6 7 8 9 Simmons, M. H. (1988). Acacias of Australia, vol. 2. Ringwood, Australia: Penguin Books Australia Ltd. p. 166.
  7. 1 2 3 4 5 6 Tame, T. (1992). Acacias of southeast Australia. Kenthurst, Australia: Kangaroo Press Pty Ltd. p. 136.
  8. 1 2 3 The Royal Botanic Gardens and Domain Trust. PlantNET - The Plant Information Network System of The Royal Botanic Gardens and Domain Trust, Sydney, Australia. Retrieved June 2012
  9. 1 2 Greig, D. (2002). A photographic guide to wildflowers of outback Australia. Sydney, Australia: New Holland Publishers (Australia) Pty Ltd. p. 71.
  10. 1 2 3 4 Moore, P. (2005). A guide to plants of inland Australia. Sydney, Australia: New Holland Publishers (Australia) Pty Ltd. p. 331.
  11. 1 2 Chapman, Alexander R.; Maslin, Bruce R. Kodela, Phillip G. (ed.). "Acacia ligulata". Flora of Australia. Australian Biological Resources Study, Department of Climate Change, Energy, the Environment and Water: Canberra. Retrieved 14 August 2026.
  12. 1 2 3 Baumer, M., (1983). EMASAR phase II. Notes on trees and shrubs in arid and semi-arid regions. Rome: Food and Agriculture Organization of the United Nations. p. 20.
  13. ↑ World Wide Wattle. Retrieved June 2012
  14. ↑ "Kings Canyon Watarrka - Better than Uluru?". Travel Outback Australia. 27 January 2022. Retrieved 10 April 2023.
  15. 1 2 "Watarrka". Central Art Aboriginal Art Store (in Indonesian). Retrieved 10 April 2023.
  16. ↑ "Kings Canyon Tourism". Discover Central Australia. Retrieved 10 April 2023.
  17. 1 2 3 World Wide Wattle. Retrieved June 2012
  18. 1 2 3 Keith, D. (2004). Ocean shores to desert dunes – The native vegetation of New South Wales and the ACT. Hurstville NSW: Department of Environment and Conservation (NSW). pp. 294-295.
  19. 1 2 3 "Florabank. Retrieved June 2012". Archived from the original on 15 February 2017. Retrieved 11 June 2012.
  20. ↑ Read, J. L., Kovac, K-J., & Fatchen, T. J., (2002), ‘Biohyets’: A holistic method for demonstrating the extent and severity of environmental impacts. p. 7.
  21. ↑ Government of South Australia, Department of Environment and Natural Resources. eFloraSA. Retrieved June 2012 Archived 2011-04-06 at the Wayback Machine
  22. ↑ Auld, T. D. (1995). The impact of herbivores on regeneration in four trees from arid Australia. The Rangeland Journal, 17(2), pp. 213-227.
  23. ↑ Western Australian Herbarium (1998). FloraBase—the Western Australian Flora. Department of Environment and Conservation. Retrieved June 2012 Archived 6 March 2012 at the Wayback Machine
  24. ↑ Davidson, D. W. & Morton, S. R., (1984). Dispersal Adaptations of Some Acacia Species in the Australian Arid Zone. Ecology, 65(4). pp. 1038-1051.
  25. ↑ Whitney, K. D., (2002). Dispersal for distance? Acacia ligulata seeds and meat ants Iridomyrmex viridiaeneu. Austral Ecology, 27. pp. 589-595.
  26. ↑ Palombo, E. W., & Semple, S. J., (2001). Antibacterial activity of traditional Australian medicinal plants. Journal of Ethnopharmacology, 77, p. 153.