The mongongo is the oil-rich, hard-shelled seed of Schinziophyton rautanenii, a large spreading tree of the dry woodlands of southern Africa. Encased in a thin, sweet, plum-like pulp and a stone-hard inner shell, the cream-coloured kernel is roasted, cracked and eaten whole or pressed for oil — and it is famous above all as a wild staple of the San (Bushmen) of the Kalahari, who have eaten it for tens of thousands of years.