An acacia tree (Acacia melanoxylon), ca.1920|植物学数据集|历史用途数据集

Photograph of an acacia tree (Acacia melanoxylon), ca.1920. The tall tree towers above the little boy that sits beneath it under its shade. The dirt ground is littered with leaves. Other trees are visible in the background.; "The Acacia tree has a very sweet smell. The leaves are soft green and it bears yellow flowers. The tree was abundant in Egypt and was found in limited numbers in deserts of Arabia. The bark is gnarled and black and rough. The plant has angular, spreading branches and many sharp thorns. The Acacia family includes many species of small trees native to arid parts of Africa and Asia. Plantations of (Acacia nilotica), the Egyptian acacia, were a familiar sight in Upper Egypt in antiquity. This small, tough, thorny tree is a plant of many uses. The bark yields tannin acid, which Egyptian used to heal burns. Livestock fatten on the seed of the large pods. The tree's sap, variously described as either milky or reddish, is a source of gum acacia, or gum arabic. This edible gum has a long history of use in food, medicine, incense, paints, and glue. Contraception was also performed by the insertion of crocodile dung, gum acacia and natron into the vagina. Gum acacia when dissolved produces lactic acid, a very effective known spermicidal." -- unknown author.