The orange is the fruit of the citrus species Citrus ? sinensis in the family Rutaceae. It is also called sweet orange, to distinguish it from the related Citrus ? aurantium, referred to as bitter orange. The sweet orange reproduces asexually (apomixis through nucellar embryony); varieties of sweet orange arise through mutations.
The pear tree and shrub are a species of genus Pyrus in the family Rosaceae, bearing the pomaceous fruit of the same name. Several species of pear are valued for their edible fruit and juices while others are cultivated as trees.