Watermelon (Cucurbita Citrullus) is an annual vine-like flowering plant species in the family Cucurbitaceae. Stems are up to 10 feet long. Plants have both male and female flowers on hairy stalks. The large fruit is a kind of modified berry called a pepo with a thick rind and fleshy center. The rind of the fruit is mid- to dark green and usually mottled or striped. The flesh can be red or pink, orange, yellow, green or white.