High Quality Content by WIKIPEDIA articles! Solanum citrullifolium is a species of nightshade commonly known as the Watermelon Nightshade, as its leaves somewhat resemble those of a watermelon plant (the Melon-leaved Nightshade is a different species, S. heterodoxum Dunal, whose leaves resemble those of a normal melon plant). It is a white-stemmed shrub with purple star-shaped flowers. It is native to the southern United States and it is grown in home gardens as an ornamental plant.