Acacia, a ka'sha, a genus of plants consisting of trees or shrubs with compound pinnate leaves and small leaflets, growing in Africa, Arabia and the East Indies and other tropical and subtropical countries. The flowers are arranged in spikes or globular heads, and grow in the axils of the leaves near the ends of the branches. The fruit is a dry, unjointed pod. Several of the species yield gum-arabic and other gums; some have puckery barks and pods that are used in tanning; an Indian species yields the valuable medicine called catechu. The wattle tree of Australia, from fifteen to thirty feet in height, is the most beautiful and useful of the species found there. Its bark contains a large percentage of tannin, and is hence exported. Some species yield valuable timber and some are cultivated for the beauty of their flowers.