Black willow roots are very bitter, and have been used as a substitute for quinine in the past. Ethnobotanical uses of black willow by various Native American tribes include basketry, and treatment of fever, headache, and coughs. It was recognized that using the bark and leaves of "Salix nigra" was useful in treating rheumatism. Early civilizations with this knowledge were able to benefit from the pain relieving effects of this tree. This is because the bark of the tree contains salicylic acid, a chemical compound similar to aspirin (acetylsalicylic acid). This Salicin compound was extracted from the bark of a black willow in 1829, before the actual invention of aspirin.