The pear is an edible fruit produced by a tree of the same name, classified as Pyrus communis in the family Rosaceae. It is native to coastal and mildly temperate regions of the Old World in Europe, Asia and North Africa. It is a medium-sized tree, reaching 10 to 17 metres (33 to 56 ft) tall, often with a narrow crown. The leaves are alternately arranged, simple, 2 to 12 centimetres (0.79 to 4.72 in) long, glossy green on some species, densely silvery-hairy in some others; leaf shape varies from broad oval to narrow lanceolate. Most pears are deciduous; however, some are evergreen. The flowers are white, rarely tinted yellow or pink, 2 to 4 centimetres (0.79 to 1.57 in) diameter, and have five petals. The fruit is composed of the receptacle or upper end of the flower-stalk (the so-called calyx tube) greatly dilated. Enclosing this is another fleshy layer, the so-called core. From the outside, the flesh of the fruit is smooth; it can range in colour from white to yellow, green, brown, red, or purple. The fruit is often considered to be a 'false berry', as the fleshy part is derived not from the ovary, but from the receptacle of the flower. The pear is an accessory fruit, meaning that the fleshy part of the fruit is not derived from the plant's ovaries. The pear is cultivated throughout the temperate world as both a fresh fruit and canned fruit product. According to Pear Bureau Northwest, about 3000 known varieties of pears are grown worldwide. China produced 58% of the world total of pears in 2016. A large majority of the varieties in cultivation originated in Europe and Asia. Pears grow in the temperate climatic regions. The main pear tree producing areas are China and the European Union. Pears have been cultivated in China for approximately 3000 years. The European pear, Pyrus communis, is believed to have arisen from two subspecies of wild pears, categorized as P. communis subsp. Pyraster and P. communis subsp. Connata. These subspecies are interfertile and the major genes controlling their phenotypes have been identified. A genetic study found that one of the ancestral parents of the European pear was the Chinese white pear (P. x bretschneideri), whereas the other was the European wild pear (P. communis subsp. Pyraster). The cultivated European pears are believed to have arisen from hybrids of these two subspecies. The genus Pyrus is thought to have originated in present-day China. The earliest archaeological evidence of pear cultivation is from the Neolithic period. Pear trees are not found in the wild in Europe, and the native range of the European pear is confined to the edge of the range of the wild Asian pear, P. pyrifolia. In the late Bronze Age, the Cucuteni-Trypillian culture flourished in the Carpathian Basin. Here, people carried out extensive cultivation of fruit trees and raised animals to supplement their diets. Pears were among the fruits that were cultivated. In the Iron Age, the Celtic Hallstatt culture flourished in parts of Central Europe, and it is here that the first evidence of pear cultivation has been found. The Hallstatt period is dated from 800 BCE to 450 BCE, and in this time, pear trees were among the first fruit trees introduced to the region. Pears began to be cultivated in north-western Europe early in the period. The rootstock used was the European Pear, P. communis subsp. Communis. In the southern part of Europe, the Common Pear, P. communis subsp. Pyraster, was used as a rootstock. The leaves of these trees were frequently used as offerings in religious shrines, and the wood was used to construct shrines and temples. The fruit of these trees was also used in religious ceremonies and as burial gifts. By the end of the period, the use of pears as food was common in the region. In the early Middle Ages, the European pear was cultivated in the Muslim world. It was here that the first evidence of grafting pears onto quince rootstocks was found. This practice was later brought to Europe. In the medieval period, pears were a highly prized food. They were often given as gifts, and pear trees were frequently planted in monastery gardens. Pears were also used in medicine, and the juice was used to make pear wine. In the late medieval period, the European pear began to be widely cultivated in North America. The first pears were brought to the region by the Spanish in the 16th century. Pears were also brought to the region by the English and the French in the 17th century. The first pear tree in North America was planted in Massachusetts in 1630. Pears are now widely cultivated in the United States. The most common variety grown in the country is the Bartlett Pear. Pears are also grown in Canada, Mexico, and South America. Pears have been cultivated in Australia and New Zealand since the 19th century. The first pear trees in Australia were planted in Tasmania in 1804. The first pear tree in New Zealand was planted in the Bay of Islands in 1819. Pears are now widely cultivated in both countries.