The size of an orange seed, normally referred to as pip, is not defined. It is the seed that is usually used to grow the orange trees which are classified as citrus fruits. The seeds are however not found in all oranges and this is said to be caused by mutation and it determines the sweetness or bitterness of the fruit.
Orange is a hybrid of ancient cultivated origin, possibly between Pomelo. It is an evergreen flowering tree generally growing to 9–10 m in height. The leaves are arranged alternately, are ovate in shape with crenulate margins and are 4–10 cm long. The orange fruit is a hesperidium, a type of berry.