The Bartlett pear, Williams' bon chretien pear, or Williams pear, is the most commonly grown variety of pear in most countries outside Asia. It is a cultivar (cultivated variety) of the species Pyrus communis, commonly known as the European pear. The fruit has a bell shape, considered the traditional pear shape in the west, and its green skin turns yellow upon later ripening, although red-skinned derivative varieties exist. It is considered a summer pear, not as tolerant of cold as some varieties. It is often eaten raw, but holds its shape well when baked, and is a common choice for canned or other processed pear uses.