ACACIA WATTLE (Acacia Auriculiformis)
This fast growing tree is commonly found everywhere, including lawns, abandoned area, wastelands and secondary forests of Singapore. It was first introduced as an ornamental from Thursday Island in the Torres Straits, Australia. It is a common tree with fissured bark, growing up to 60 feet in height. This tree has no leaves except when it is a seedling. When the seedling first sprouts, it has twice pinnate leaves. Subsequent leaves have enlarged leaf stalks with a little bit of true leaves and by the fifth "leaflet", it's all leaf stalk and no leaf! These flattened leaf stalks called phyllodes, are green and function as leaves. These are an adaptation to hot climates and droughts. The tree flowers quickly, within 1-2 years. The tiny yellow flowers are fragrant and are gathered in clusters. Pods when ripe, turn from yellow to brown and curl up. Black seeds are hung on short curled orange stalks when the pod splits open. Birds find these seeds highly attractive and eat them. Thus the plant is very quickly dispersed.
Aborigines of Australia have traditionally harvested the seeds of some acacia species as food. These are ground into flour and eaten as a paste or baked into a cake. The seeds can contain 25% more protein than common cereals like rice or wheat, and their hard seed coats mean acacia seeds also store well for long periods. Acacias were purposely introduced and planted in Southeast Asia and Oceania as a source of firewood and good quality charcoal (does not smoke), as well as timber for furniture and pulp for making paper (acacia produces high yields of pulp and produces strong paper). The tannin produced from the tree is of a good quality, but tends to redden with exposure to sunlight. The tree was also introduced as an ornamental shade tree, but in Singapore, it is no longer grown as a wayside tree due to the large amount of litter of "leaves", flowers and fruits that the tree produces.
In India, the tree was cultivated to feed the lac insect, which produces a resinous secretion that is harvested to produce lacquer. The Aborigines of Australia uses a decoction of the root to treat aches and pains and sore eyes; an infusion of the bark to treat rheumatism.
Acacia has the potential to protect poor soils from erosion and revive their mineral content. Acacia can grow on poor soils including clay, limestone and unstable sand dunes, even soil tainted with uranium wastes. It is also able to survive fire, dry spells and seasonally waterlogged soil. (In fact, the seeds germinate better when placed in hot ashes!). The tree also contains
nitrogen fixing bacteria which can help rejuvenate these poor soils. The tree prevents soil erosion because of their extensive and dense roots and heavy leaf litter. But the seedlings don't grow well in the shade and in competition with weeds, so for deliberate planting, the seedlings have to be raised elsewhere first. Acacias recover wastelands, returning nutrients to poor soils and providing shade for other plants to take hold. They do not produce a lot of pollen or nectar as food, but their plentiful seed supply is a valuable food source for animals (mainly birds and also small mammals), particularly in dry places. Various insects eat their leaves and wood, and sugar gliders and squirrels may eat their sap. The trees also provide shelter for animals; as well as epiphytic plants.
Aborigines of Australia have traditionally harvested the seeds of some acacia species as food. These are ground into flour and eaten as a paste or baked into a cake. The seeds can contain 25% more protein than common cereals like rice or wheat, and their hard seed coats mean acacia seeds also store well for long periods. Acacias were purposely introduced and planted in Southeast Asia and Oceania as a source of firewood and good quality charcoal (does not smoke), as well as timber for furniture and pulp for making paper (acacia produces high yields of pulp and produces strong paper). The tannin produced from the tree is of a good quality, but tends to redden with exposure to sunlight. The tree was also introduced as an ornamental shade tree, but in Singapore, it is no longer grown as a wayside tree due to the large amount of litter of "leaves", flowers and fruits that the tree produces.
In India, the tree was cultivated to feed the lac insect, which produces a resinous secretion that is harvested to produce lacquer. The Aborigines of Australia uses a decoction of the root to treat aches and pains and sore eyes; an infusion of the bark to treat rheumatism.
Acacia has the potential to protect poor soils from erosion and revive their mineral content. Acacia can grow on poor soils including clay, limestone and unstable sand dunes, even soil tainted with uranium wastes. It is also able to survive fire, dry spells and seasonally waterlogged soil. (In fact, the seeds germinate better when placed in hot ashes!). The tree also contains
nitrogen fixing bacteria which can help rejuvenate these poor soils. The tree prevents soil erosion because of their extensive and dense roots and heavy leaf litter. But the seedlings don't grow well in the shade and in competition with weeds, so for deliberate planting, the seedlings have to be raised elsewhere first. Acacias recover wastelands, returning nutrients to poor soils and providing shade for other plants to take hold. They do not produce a lot of pollen or nectar as food, but their plentiful seed supply is a valuable food source for animals (mainly birds and also small mammals), particularly in dry places. Various insects eat their leaves and wood, and sugar gliders and squirrels may eat their sap. The trees also provide shelter for animals; as well as epiphytic plants.