1.2- Genus Citrullus – Watermelon + Overview Citrullusis a genus of four species ofdesertvines, among whichCitrullus lanatus(the watermelon) is an important crop. Recent molecular data, including sequences from the original collection ofCitrullus lanatus, made by C. P. Thunberg in 1773, show that this plant is not a watermelon, but instead a bitter melon, as implied by Thunberg's original description of the species. Synonyms AnguriaMill. ColocynthisMill. + Species 1- Citrullus colocynthis 2- Citrullus ecirrhosus 3- Citrullus lanatus- Watermelon 4- Citrullus naudinianus.