Lemon, (Citrus ×limon), small tree or spreading bush of the rue family (Rutaceae) and its edible fruit. Lemon juice is a characteristic ingredient in many pastries and desserts, such as tarts and the traditional American lemon meringue pie. The distinctive astringent flavour of the fruit, either fresh or preserved, is also used to enhance many poultry, fish, and vegetable dishes worldwide. Lemonade, made with lemon, sugar, and water, is a popular warm-weather beverage, and the juice itself is commonly added to tea. Citric acid may amount to 5 percent or more by weight of the lemon’s juice, which is also rich in vitamin C and contains smaller amounts of the B vitamins, particularly thiamin, riboflavin, and niacin. The lemon was introduced into Spain and North Africa sometime between the years 1000 and 1200 CE. It was further distributed through Europe by the Crusaders, who found it growing in Palestine. In 1494 the fruit was being cultivated in the Azores and shipped largely to England. The lemon was thought by 18th-century Swedish botanist Carolus Linnaeus to be a variety of citron (Citrus medica), though it is now known to be a separate hybrid species.