This genus is very similar to Citrullus in its morphological characters, but differs in the stratification of pollen grains, haploid chromosome number and to some extent in leaf morphology. In Citrullus the pollen grains are reticulate, haploid chromosome number is 11 and the leaves are deeply pinnatipartite while in Praecitrullus pollen grains are echinate, haploid chromosome number is 12 and the leaves are sparingly pinnatifid. The seeds are also devoid of the enzyme urease which is commonly found in the genus Citrullus (Jeffrey in Kew Bulletin 20(3): 42. 1966) and the seed coat is 3-layered, not 4-layered as in Citrullus (C. Jeffrey in Kew Bulletin 30(3): 476-478. 1975.)
A monotypic genus, distributed in India and Pakistan.