Acacia coriacea

Acacia coriacea, commonly known as wirewood, wiry wattle or desert oak, is a species of flowering plant in the family Fabaceae and is endemic to northern Western Australia. It is a spreading shrub or tree with thin bark, linear to very narrowly elliptic phyllodes, spherical heads of pale lemon yellow or cream-coloured flowers and twisted, curved or coiled pods resembling a string of beads. Indigenous Australians know the plant as Gunandru.

Description

A shrub or small tree. It grows 5 m tall. There are prickles along the stem. The leaves are twice divided and there are 8-18 pairs of pinnae. There are up to 50 pairs of pinnules on each pinnae. The flowers are yellow. They are in large clusters at the ends of branches. The pods are flattened.

Edible Uses

Seeds and flowers are both edible. The seed is cooked and is sweet and nutritious, containing about 20% protein. Seeds range from 4–10mm long and 4–6mm wide. Acacia seeds in general are highly nutritious, containing approximately 26% protein, 26% available carbohydrate, 32% fibre, and 9% fat. The fat content is higher than most legumes, with the aril contributing the bulk of largely unsaturated fatty acids — a health advantage, though these fats oxidise readily in storage. Total mean carbohydrate content of 55.8 ±13.7% is lower than lentils but higher than soybeans, while mean fibre content of 32.3 ±14.3% exceeds that of lentils (11.7%). Energy content averages 1480 ±270 kJ per 100g. Wattle seeds are low glycaemic index foods — starch is digested slowly, producing a small, sustained rise in blood glucose and delaying exhaustion during prolonged exercise. Flowers are cooked; rich in pollen, they are often used in fritters.

Traditional Uses

The seeds are eaten after being crushed into flour. They can be eaten raw when young or roasted when mature. They can also be steamed in the green pods and eaten like peas.

Medicinal Uses

None known.

Known Hazards

The seed of many Acacia species, including this one, is edible and highly nutritious, and can be eaten safely as a fairly major part of the diet. Not all species are edible, however, and some can contain moderate levels of toxins. Especially when harvesting from the wild, especial care should be taken to ensure correct identification of any plants harvested for food. Especially in times of drought, many Acacia species can concentrate high levels of the toxin Hydrogen cyanide in their foliage, making them dangerous for herbivores to eat.

Distribution

It is a warm temperate plant. It grows in deep, red, sandy soils. It grows naturally in arid and semi arid regions. Soils need to be well drained. It is drought tolerant. It can grow in arid places.

Where It Grows

Africa, Australia, Tasmania, Senegal, West Africa,

Cultivation

Prefers a sandy loam and a very sunny position. Succeeds in dry soils. Succeeds in any good garden soil that is not excessively limey. Most species become chlorotic on limey soils. Trees are very tolerant of maritime exposure in their native environment, though they are often severely wind-shaped and can be semi-prostrate. Trees are not very hardy outdoors in Britain, even in the mildest areas of the country they are likely to be killed in excessively harsh winters. This is one of the most drought-tolerant tropical acacias of North and North West Australia, being able to survive years with no more than 50 mm of rain in 20 days in its native area of distribution. Rainfall in its native habitat varies from 200 to 500 mm. This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby.

Propagation

Seed is best sown as soon as ripe in a sunny position in a warm greenhouse. Stored seed should be scarified, pre-soaked for 12 hours in warm water, then sown in a warm greenhouse in March. Germination occurs in 3–4 weeks at 25°C. Prick out seedlings into individual pots when large enough to handle and grow on in a sunny greenhouse position for at least their first winter. Plant out in early summer, with some protection from winter cold advisable for the first year or two. Cuttings of half-ripe wood with a heel can be taken in July/August, potted individually in a frame, overwintered in a greenhouse, and planted out in late spring or early summer. Fair success rate.

Other Uses

A yellow dye is obtained from the flowers, and a green dye from the seed pods. The plant's extensive root system helps prevent soil erosion. The wood has been used to make small tools and implements.

Production

Plants can flower within 2 years of planting.

Notes

There are about 1,350 Acacia species. Over 1,000 occur in Australia. Also as Mimosaceae.

Nutrition

Also Known As

Awenth ntjirrima, Desert Oak, Dogwood, Irrkili, Kunapuka, Mulupuka, Ntjirrima, Pungkuna, Wirewood, Wiry wattle, Yirrkali

References (26)

• Anon., 2003, Native Plants for the Fitzroy basin. Society for Growing Australian Plants Inc. (Rockhampton Branch)
• Bindon, P., 1996, Useful Bush Plants. Western Australian Museum. p 9
• Bonney, N., 1997, Economic Native Trees and Shrubs for South Australia. Greening Australia (SA) inc. Campbelltown SA 5074 p 4
• Cancilla, D., 2018, Ethnobotanical and Ethnozoological Values Desktop Assessment - Eliwana Project. p 9
• Cherikoff V. & Isaacs, J., The Bush Food Handbook. How to gather, grow, process and cook Australian Wild Foods. Ti Tree Press, Australia p 36, 46, 188

More from Fabaceae

Abrus pulchellus

Malay licorice

Acacia abyssinica

Flat-top acacia

Acacia acatlensis

Chondata

Acacia acradenia

Acacia acuminata

Raspberry jam wattle

Acacia adoxa