Prenia vanrensburgii, the sea pumpkin is often seen on coastal sand between Hawston and Cape Agulhas. While the species is still common, its habitat is encroached upon by much human activity and coastal development as well as competition from alien invasive plants.

The sea pumpkin has creeping branches with erect obovate, succulent leaves and acute tips, blue-green in colour. The flowers are small with white petals and slightly creamy centres (Smith, et al, 1998; http://redlist.sanbi.org).