Citrullus is a genus of four species of desert vines, among which Citrullus lanatus (the watermelon) is an important crop. Recent molecular data, including sequences from the original collection of Citrullus lanatus, made by C. P. Thunberg in 1773, show that the plant originally dubbed Citrullus lanatus was not a watermelon, which the name now refers to, but instead a bitter melon, as implied by Thunberg's original description of the species.