Excavations at the Border Cave, about 400 kilometres north-northeast of Durban, South Africa, have revealed 55 small charred cylinders which researchers recognised as rhizomes. All appear to belong to the same species, identified as Hypoxis, commonly called the Yellow Star flower. Hypoxis rhizomes are an ideal staple plant food - nutritious and carbohydrate-rich. They are edible raw, but fibrous and tough unless cooked. They were mostly recovered from fireplaces and ash dumps, suggesting they were roasted in ashes.
     The site has been repeatedly excavated since 1934. Amongst earlier discoveries were the burial of a baby with a Conus seashell at 74,000 years ago, a variety of bone tools, an ancient counting device, ostrich eggshell beads, resin, and poison that may once have been used on hunting weapons. One digging stick  found at the cave has been dated to around 40,000 years ago.
     Unlike the more common deciduous species, Hypoxis angustifolia is evergreen, so has visibility year-round. The rhizomes grow in clumps, so many can be harvested at once. It thrives in a variety of modern habitats and is likely to have had wide distribution in the past. It occurs in sub-Saharan Africa, south Sudan, and some Indian Ocean islands. Its presence in Yemen may imply even wider distribution during previous humid conditions.
     Border Cave is a heritage site with a small museum. Both are open to the public by appointment.

Edited from EurekAlert! (2 January 2020)