Citrullus Schrad.
Citrullus is a small genus of three to five species, native to the tropics of Africa and parts of Asia. Some species are grown for their edible fruits (incl. Citrullus lanatus; watermelon) and are economically important.
Literature:
Jørgensen P.M. & Whitehouse C.M. (1997) Citrullus. In: Cullen J. & al. (eds.), The European Garden Flora, vol. 5. Cambridge University Press, Cambridge: 293.
Nesom G. (2011) Towards consistency of taxonomic rank in wild/domesticated Cucurbitaceae. Phytoneuron 2011-13: 1-33. [available online at: http://www.phytoneuron.net/PhytoN-CucurbConsistency.pdf]
Nesom G. (2015) Citrullus. In: Flora of North America Editorial Committee (eds.), Flora of North America North of Mexico, vol. 6. Oxford University Press, New York: 41-44. [available online at: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=107163]
Renner S.S., Sousa A. & Chomicki G. (2017) Chromosome numbers, Sudanese wild forms, and classification of the watermelon genus Citrullus, with 50 names allocated to seven biological species. Taxon 66(6): 1393-1405.