Citrullus amarus

About

The citron melon, also called fodder melon, preserving melon, red-seeded citron, jam melon, stock melon, Kalahari melon or tsamma melon, is a relative of the watermelon. It is from the family Cucurbitaceae which consists of various squashes, melons, and gourds. Native to arid landscapes of sub-Saharan Africa, it has been a wild source of nutrition and hydration for humans for an extraordinarily long time. Its fruit has a hard white flesh, rendering it less likely to be eaten raw in the modern era; more often it is pickled or used to make fruit preserves, and is used for cattle feed. It is especially useful for fruit preserves, because it has a high pectin content.

Summary from Wikipedia