This is a willow tree. It had been known for centuries that chewing its leaves or bark could relieve a person’s headaches and fever. Beginning in the 1830s, and culminating in 1899, European chemists isolate the molecule responsible, salicylic acid. Later it was slightly modified chemically, to acetyl-salicylic acid. Thus, aspirin was brought into the world. In addition to its original use against pain and fever, aspirin was later found useful for blood thinning in patients at risk of heart attack and stroke, and for prevention of certain types of cancer. Please don’t eat this willow tree—we have only one. You can buy aspirin at the nearby Akadamon.