Source University of the Witwatersrand.
Border Cave in the Lebombo Mountains. Photo Ashley Kruger.
  • Wits archaeologists found charred rhizomes during excavations at the Border Cave in the Lebombo Mountains.
  • The discovery gives insight into the behavioural practices of early modern humans in southern Africa. 
  • While they are edible raw, the rhizomes are fibrous and tough until cooked. Which is why the researchers think the rhizomes would have been cooked in the ashes of fireplaces.
  • For more visit Business Insider South Africa.


A remarkable discovery made by Wits archaeologists has revealed that Paleolithic humans were braaiing starchy food – and not just meat – as far back 170,000 years ago.

The discovery was made by a team of researchers led by Lyn Wadley, a scientist from the Wits Evolutionary Studies Institute at the University of the Witwatersrand.

Source University of the Witwatersrand.
Border Cave in the Lebombo Mountains. Photo Ashley Kruger.

The team successfully identified whole charred rhizomes, which are starch-enriched plant stems found underground, during excavations at the Border Cave in the Lebombo Mountains on the border of KwaZulu-Natal, South Africa and eSwatini.

In a university newsletter, Wadley said the discovery is much older than earlier reports for cooking similar plants, which gives insight into the behavioural practices of early modern humans in southern Africa.  

Since 2015 the researchers have found 55 small, charred cylinders mostly recovered from fireplaces and ash dumps rather than from surrounding sediment.

They spent four years identifying the rhizomes and found them to be Hypoxis, commonly called the Yellow Star flower. They analysed their size, shape, and vascular structure under a scanning electron microscope. The results has now been published in the peer-reviewed journal Science.

“It is extraordinary that such fragile plant remains have survived for so long,” said scientist Christine Sievers, also from Wits, and who completed the archaeobotanical work with Wadley.

While they are edible raw, the rhizomes are fibrous and extremely tough. That is why the researchers think the rhizomes would have been dug out from the nearby hillside and carried back to the cave to be cooked in the ashes of fireplaces. They then were buried, forgotten, and preserved for some 170,000 years before the scientists found them.

“Cooking the fibre-rich rhizomes would have made them easier to peel and to digest so more of them could be consumed and the nutritional benefits would be greater,” says Wadley. “The fact that they were brought back to the cave rather than cooked in the field suggests that food was shared at the home base.”

Photo Lyn Wadley
Hypoxis angustifolia growth habit. Photo Lyn Wadley/ source University of the Witwatersrand.

The most likely of the species growing in KwaZulu-Natal today is Hypoxis angustifolia that is favoured as food. It has small rhizomes with white flesh that is more palatable than the bitter, orange flesh of rhizomes from the better known medicinal Hypoxisspecies, which is incorrectly called the African Potato.

The rhizomes are rich in starch with an energy value of approximately 500 kilojoules per 100 grams.

Hypoxis can be found spread across well-watered areas of sub-Saharan Africa and in Yemen as well as farther north during moist periods. It suggests that rhizomes could have been a ready and reliable carbohydrate source for Paleolithic humans as well as perhaps facilitating the mobility of human populations, according to the abstract in Science.

Source University of the Witwatersrand.
Excavations in the Border Cave in the Lebombo Mountains in South Africa. Source: University of the Witwatersrand.

Border Cave is open to the public, though bookings are essential.

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