Noun
A genus of rosaceous trees and shrubs having pomes for fruit. It includes the apple, crab apple, pear, chokeberry, sorb, and mountain ash.
Source: Webster's dictionaryThree common types of pears are grown throughout the U.S.--the “Common” or European pear (pyrus communis), the Oriental pear (pyrus serotina), and the Asian pear (pyrus pyrifolia). Source: Internet
The Bradford pear ( Pyrus calleryana 'Bradford') in particular has become widespread in North America, and is used only as an ornamental tree, as well as a blight-resistant rootstock for Pyrus communis fruit orchards. Source: Internet
The Manchurian or Ussurian Pear, Pyrus ussuriensis (which produces unpalatable fruit) has been crossed with Pyrus communis to breed hardier pear cultivars. Source: Internet