It comes from Spiraea, a biological genus of shrubs that includes natural sources of the drug's key ingredient: salicylic acid. This acid, resembling what's in modern-day aspirin, can be found in jasmine, beans, peas. clover and certain grasses and trees. A precursor to aspirin found in leaves from the willow tree has been used for its health effects for at least 2,400 years. In 1853 chemist Charles Frédéric Gerhardt treated the medicine sodium salicylate with acetyl chloride to produce acetylsalicylic acid for the first time. For the next fifty years, other chemists established the chemical structure and came up with more efficient production methods. In 1897, scientists at the Bayer company began studying acetylsalicylic acid as a less-irritating replacement medication for common salicylate medicines. By 1899 Bayer had named it "Aspirin" and sold it around the world. Aspirin's popularity grew over the first half of the twentieth century leading to competition between many brands and formulations.