The desert Hottentot bread plant stores vast amounts of water in a large, underground corky tuber.
“Swollen roots are used by a great number of plants as storage tanks. Beneath the sand, they are out of sight and not easily found by thirsty animals living on the surface. Hottentot bread is the name given to a yam that develops an immense underground tuber that may weigh as much as seven hundred pounds and fully justifies its specific name of elephantipes — elephant foot. Every desert — in Australia and South America, in the Sahara, the Gobi and Madagascar — has such plants. And in every one, an ability to recognise the leaf of a tiny sprig standing unobtrusively in the sand as an indication of a buried water store was once the traditional life-saving knowledge of nomadic people.” (Attenborough 1995:269)