Acacia decurrens (Acacia bark, Early black wattle, Green wattle, Sydney wattle, Wattle bark) is a perennial tree or shrub native to the Greater Blue Mountains Area, which is a World Heritage Site in the Blue Mountains of New South Wales, Australia. It is also found in Africa, the Americas, Europe, New Zealand & the Pacific, the Indian Ocean area, and Japan. It grows to a height of 2-10m and it flowers from July to September.
Uses for it include chemical products, environmental management and wood. The flowers are edible and are used in fritters. An edible gum oozes out of the tree's trunk and it can be used as a lesser-quality substitute for Gum Arabic, for example in the production of fruit jelly. The tree's bark has astringent properties, but it has to be stored for a year before it can be made use of. It is used as an anti-diarrheal medicine. The bark contains about 37-40% tannin. The flowers are used to produce yellow dye and the seed pods are used to produce green dye. An organic chemical compound called Kaempferol is what gives the flowers of Acacia decurrens their color.
Cultivation of Acacia decurrens can be started by soaking its seeds in warm water and sowing them outdoors. The seeds keep their ability to germinate for many years.