Watermelon (Citrullus lanatus) is a scrambling and trailing vine in the flowering plant family Cucurbitaceae. The species was long thought to have originated in southern Africa, but this was based on the erroneous synonymization by L. H. Bailey (1930) of a South African species with the cultivated watermelon.
The error became apparent with DNA comparison of material of the cultivated watermelon seen and named by Linnaeus and the holotype of the South African species. There is evidence from seeds in Pharaoh tombs of watermelon cultivation in Ancient Egypt. Watermelon is grown in tropical and subtropical areas worldwide for its large edible fruit, also known as a watermelon, which is a special kind of berry with a hard rind and no internal division, botanically called a pepo.
The sweet, juicy flesh is usually deep red to pink, with many black seeds, although seedless varieties have been cultivated. The fruit can be eaten raw or pickled and the rind is edible after cooking.
As far as fruits go, watermelon is one of the lowest in calories - only 46 calories per cup (154 grams). That's lower than even low-sugar fruits such as berries .
One cup (154 grams) of watermelon has many other nutrients as well, including these vitamins and minerals:
Vitamin C: 21% of the Reference Daily Intake (RDI)
Vitamin A: 18% of the RDI
Potassium: 5% of the RDI
Magnesium: 4% of the RDI
Vitamins B1, B5 and B6: 3% of the RDI