"Chemist Albert Hofmann, working at the Sandoz Corporation pharmaceutical laboratory in Switzerland, first synthesized LSD in 1938. He was conducting research on possible medical applications of various lysergic acid compounds derived from ergot, a fungus that develops on rye grass. Searching for compounds with therapeutic value, Hofmann created more than two dozen ergot-derived synthetic molecules. The 25th was called, in German, Lyserg-Säure-Diäthylamid 25, or LSD-25."

Source

"Hallucinogens and Dissociative Drugs, including LSD, PCP, Ketamine, Dextromethorphan," National Institute on Drug Abuse Research Report Series. Rockville, MD: U.S. Department of Health and Human Services, Public Health Service, National Institutes of Health, 2001.