Kinds of Citrus Fruits

Trees in the genus Citrus are wonderfully variable and prone to form hybrids with each other, which makes it a challenge for scientists to work out family relationships. Currently it’s thought that the common domesticated citrus fruits all derive from just three parents: the citron Citrus medica, the mandarin orange Citrus reticulata, and the pummelo Citrus maxima. At least one offspring is relatively young: the grapefruit apparently originated in the West Indies in the 18th century as a cross between the pummelo and the sweet orange.