Any of approximately 20 species of deciduous tree fruits in the genus Pyrus. About half of the species are native to Europe, North Africa, and the Middle East around the Mediterranean Sea; the others are native to Asia. Pear culture is documented to have started as early as 1100 B.C. Pears are best adapted to temperate climates with warm, dry summers and cold winters. They require winter cold to break the dormant period but are injured by temperatures below −10 to −15°F (−23 to −26°C). Commercial pear production in the United States is concentrated in the interior valleys of California, Oregon, and Washington.