Apples are pome fruits, not citrus fruits. Pomes are members of the plant family Rosaceae, while citrus fruits belong to the plant family Rutaceae.
Pome fruits are those with a core of several small seeds surrounded by a tough membrane, which is encased by an edible layer of flesh. Apples and pears are the two most common pomes. Citrus fruits are acidic with seeds covered by juicy, bitter fruit segments known for their strong fragrance. Citrus fruits include citron, lemon, lime, orange and grapefruit. Both pome and citrus fruits are rich in vitamin C and considered healthy additions to any diet.