MERCURY POISONING; MUSHROOM POISONING.
poison hemlock Any of several poisonous herbaceous plants of the parsley family, especially Conium maculatum, believed to be the plant that killed Socrates. It is now common in the U.S. as well as in Europe. A tall biennial, this plant has green stems spotted with red or purple, large com¬ pound leaves, and white flowers. Though the poison is concentrated in the seeds, the entire plant is dangerous to livestock when fresh. Despite their common name, poison hemlocks are not conifers (see hemlock). Water hemlocks (Cicuta species) are similar and also dangerous.
poison ivy Either of two North American species of white-fruited woody vines or shrubs of the sumac, or cashew, family. The species found
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1518 I poison oak ► Poland
in eastern North America ( Toxico¬ dendron radicans) is abundant; a western species, known as poison oak, is less common. Both species are sometimes classified as genus Rhus. A key identifier is leaves with three mitten-shaped leaflets. Contact with urushiol, an oil produced by the plant, can cause severe inflammation and blistering of human skin. Urush¬ iol may be carried from the plant on clothing, shoes, tools, or soil; by ani¬ mals; or by smoke from burning plants. Because urushiol is nonvola¬ tile, a reaction may result from wear¬ ing clothing a year or more after its contact with the plant.
poison oak Species of poison ivy ( Toxicodendron diversilobum) native to western North America and classified in the sumac (or cashew) family. Like many other lobe-leafed plants commonly called oak, poison oak is not an OAK tree (genus Quercus).
poison sumac also called poison elder Attractive, narrow shrub or small tree ( Rhus vernix or Toxicodendron vernix ) of the sumac, or cashew, family. It is native to swampy acidic soils of eastern North America. Unlike the upright reddish, fuzzy fruit clusters of other sumacs, whitish waxy berries droop loosely from its stalks. The clear sap, which black¬ ens on exposure to air, is extremely irritating to the skin for many people.
Poitier \'pwa-te-,a\, Sidney (b. Feb. 20, 1927?, Miami, Fla., U.S.) U.S. actor. He was raised in The Bahamas, then studied and acted with the American Negro Theatre in New York City. He made his film debut in No Way Out (1950) and gave notable performances in Blackboard Jungle (1955) and The Defiant Ones (1958). He won acclaim on Broadway for his role in A Raisin in the Sun (1959). He became the first African Ameri¬ can actor to win an Academy Award, for his role in Lilies of the Field (1963). He used his critical and commercial success to push for integrated film crews. He went on to star in notable films such as In the Heat of the Night (1967), To Sir with Love (1967), and Guess Who’s Coming to Din¬ ner (1967). He also directed several films, including Buck and the Preacher (1972), Let’s Do It Again (1975), and Stir Crazy (1980). In 1997 he was appointed The Bahamian ambassador to Japan.
Poitiers, Battle of (732) See Battle of Tours/Poitiers
Poitiers \pwa-'tya\, Battle of (September 19, 1356) Catastrophic defeat of the French king John II in the Hundred Years' War between France and England. English troops under Edward the Black Prince were under pursuit from the probably superior French forces. South of Poitiers the English secured themselves in thickets and marshes, where the French knights became bogged down and made easy targets for the English archers. John II was taken prisoner and for his freedom had to consent to the disadvantageous Treaties of Bretigny and Calais.
Poitou \pwa-'tu\ Historical region, western central France. It was bounded by Brittany, Anjou, Touraine, Marche, and the Atlantic Ocean. It was inhabited by the ancient Gallic tribe of Pictones and became part of Roman Aquitania. A meeting place of northern and southern cultures, its golden age (11th—12th century) was characterized by great Romanesque art and architecture. The counts of Poitiers were succeeded by the Angevin kings of England, but by 1375 the French had won the region back. It was a province of France until the French Revolution, when it was divided into three departments. It is predominantly a rural area; regional specialties include seafood and white wine.
poker Any of several card games in which a player bets that the value of his or her hand is greater than that of the hands held by others. Each subsequent player must either equal or raise the bet or drop out. The pot is eventually won by either the player showing the best hand when it comes to a showdown or the only player left when everyone else has dropped out, or “folded.” In this case the winner need not show his hand and could conceivably have won the pot with a lower hand than any other at the table. It is for this reason that poker is described as a game of bluff. Three principal forms of the game have developed: straight poker, in which all cards of the standard five-card hand are dealt facedown; stud poker, in which some but not all of a player’s cards are dealt faceup; and
Poison ivy (Toxicodendron radicans)
WALTER CHANDOHA
community-card poker, in which some cards are exposed and used by all the players to form their best hand. In draw poker, the main variant of straight poker, cards may be discarded and additional cards drawn. The traditional ranking of hands is (1) straight flush (five cards of the same suit in sequence, the highest sequence—ace, king, queen, jack, ten—being called a royal flush), (2) four of a kind, (3) full house (three of a kind, plus a pair), (4) flush (five of a single suit), (5) straight (five in sequence), (6) three of a kind, (7) two pair, (8) one pair.
pokeweed also called pokeberry or poke Strong-smelling shrub¬ like plant ( Phytolacca americana) with a poisonous root resembling the shape of horseradish, native to wet or sandy areas of eastern North America. It has white flowers, reddish black berries, and dark green leaves that often are red-veined or borne on red leafstalks. The berries contain a red dye used to colour wine, candies, cloth, and paper. Like the roots, the red or purplish mature stalks are poisonous. Very young green shoots (up to about 6 in. [15 cm]), however, are edible.
Pokrovsky Cathedral See Saint Basil the Blessed
Pol Pot orig. Saloth Sar (b. May 19, 1925/28, Kompong Thom prov¬ ince, Cambodia—d. April 15, 1998, near Anlong Veng) Prime minister of Cambodia. He joined the anti-French resistance under Ho Chi Minh in the 1940s and became a member of the Cambodian Communist Party in 1946. After studying radio technology in Paris, he returned to Cambodia in 1953 and taught French until he fell under police suspicion in 1963. For the next 12 years he built up the Communist Party. U.S. anticommunist activity in Cambodia in the early 1970s, including helping to depose Norodom Siha¬ nouk and a bombing campaign in the countryside, drove many to join him. In 1975 his Khmer Rouge forces captured Phnom Penh, which he ordered entirely evacuated. Even the sick were wheeled out in hospital beds, and in the first weeks it is estimated that tens of thousands died. The ruthlessness with which he pursued his intention to return to “year zero” and create an ethnically pure, agrarian, communist state resulted in the deaths of one to two million people. Overthrown by the Vietnamese in 1979, he led an anti- Vietnamese guerrilla war until he was repudiated by the Khmer Rouge and sentenced to life imprisonment (1997); he died the next year.