Crinum leaves are basal, typically long and strap-shaped, with colors ranging from light green to green.

Cytological studies have shown that 27 species of Crinum are diploid, having a typical chromosome count of 2n = 22. Abilio Fernandes found that the Orange River Crinum bulbispermum had a count of 2n = 66, and some desert Crinum macowanii 2n = 44. These polyploid species produce seeds that are often parthenogenetic triploid or diploids, lack Vigor and seldom grow to mature plants.