The grapefruit (Citrus × paradisi) is a subtropical citrus tree known for its relatively large, sour to semisweet, somewhat bitter fruit. The interior flesh is segmented and varies in color from pale yellow to dark pink. Grapefruit is a citrus hybrid originating in Barbados as an accidental cross between the sweet orange (C. sinensis) and the pomelo or shaddock (C. maxima), both of which were introduced from Asia in the 17th century. When found, it was called the forbidden fruit. In the past, it was referred to as the pomelo, but that term is now the common name for Citrus maxima.
 

Fruits III

In botany, a fruit is a seed-bearing structure in flowering plants formed from the ovary after flowering.

Fruits are how flowering plants disseminate their seeds. Edible fruits, in particular, have long propagated using the movements of humans and animals in a symbiotic relationship that is the means for seed dispersal for the one group and nutrition for the other; in fact, humans and many animals have become dependent on fruits as a source of food.