Salt Wattle, Jila Jila, Nyarlka
This acacia is restricted to north-western Western Australia and the Northern Territory along the coast and in scattered localities throughout dry inland areas. The latitudinal range is 16-26o S and it is found from near sea level to about 400 m. (WA, NT).
A fast-growing, dense shrub or small tree, 3-9 m tall with up to four stems and a spreading crown. The canopy is distinctively dark green, and the branchlets smooth and yellowish. Phyllodes are usually linear to lanceolate, 7-25 cm long and 7-30 mm wide, with a prominent yellow midrib. The flowers are white or cream in globular heads. Pods are hard, grey-brown, 7-10 cm long and 5 mm wide. The main flowering period is May - August. The black shiny seeds have a distinctive scarlet aril. There are about 34 000 viable seeds per kilogram. Seeds need pre-treatment with boiling water for one minute to promote germination. This species can spread by root suckering and coppices easily.
Ecology/Way of Life:
It occurs mainly in warm to hot, semi-arid and arid zones. Mean annual rainfall is 250-700 mm with a summer maximum. The dry season is 5-9 months but this acacia usually occurs on sites receiving additional run-on water. The area is frost-free. It is found on sand plains, flood plains and along drainage lines. Soils are mainly alluvial, either sandy or clayey, and typically strongly alkaline. It is one of the most salt-tolerant acacias and grows close to the tidal zone and is associated with inland salt lakes. Acacia ampliceps is most frequently found in fringing communities along drainage lines, in chenopod or acacia dominated shrublands, and open-woodland.
Interaction with Humans/Threats:
A useful species for fuelwood, low windbreaks, sand dune and saline wasteland rehabilitation, and fodder. Aboriginal people use the seeds for food, generally ground to paste but sometimes chewed without preparation. Recently it has been used to revegetate salt-affected land in Pakistan.
It seeds freely and grows rapidly which suggests it has the potential to become a weed in some situations.
(named in 1974 by Dr. Bruce Maslin, Western Australian Herbarium; based on Greek: akakia = thorny plant, specifically Acacia arabica; and Latin: amplus = large, referring to the large flower heads).
Doran, J.C. and Turnbull, J.W. (eds.) 1997. Australian trees and shrubs; species for land rehabilitation and farm planting in the tropics. ACIAR Monograph no. 24. Australian Centre for International Agricultural Research, Canberra. 384 pp.
Marcar, N.E., Ismael, S., Hossain, A.K.M.A. and Ahmad, R. 1999. Trees, shrubs and grasses for salt lands: an annotated bibliography. ACIAR Monograph no. 56. Australian Centre for International Agricultural Research, Canberra. 316 pp.
Maslin, B.R. 1974. Studies in the genus Acacia. 2. Miscellaneous new phyllodinous species. Nuytsia 1: 315-318.
Topics:Aboriginal resources Soils Vegetation types Timber Germination
Text & map from Australian Trees and Shrubs, courtesy Australian Centre for International Agricultural Research; text edited by J. Turnbull; photo courtesy T. Vercoe.
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