Poison-Ivy/Poison-Oak/Poison-Sumac—The Virulent Weeds

The word poison entered the English language in 1387 as ‘poysoun”, and in Memoirs of American Academy of Arts and Sciences, v. 1, 1785, the word poison-ivy was used for the first time: “Poison ivy … produces the same kind of inflammation and eruptions … as poison wood tree”.The first known reference to poison-ivy, Toxicodendron radicans (L.) Ktze., dates from the 7th century in China and the 10th century in Japan. Since Toxicodendron species do not grow in Europe, the plants remained unknown to Western civilization until explorers visited the New World seven centuries later. Capt. John Smith (1579–1631) wrote the first description of poison-ivy and originated its common name; he noted a similarity in the climbing habit of North American poison-ivy to English ivy (Hedera helix L.).