Istwa Nou

Crops domesticated in West Africa had taken root in southern Arabia by 3000 BCE. Once they were established in Yemen and Oman they went aboard ship, and before the third millennium was out they were growing on the Indian subcontinent. The archaeologist Dorian Fuller and his colleagues assembled the evidence: a sphere of intercontinental contact more than four thousand years old, running from Africa through southern Arabia into South Asia. The usual account of ancient long-distance trade opens with Mesopotamia and the Indus valley and gives Africa a line in the notes. Fuller's material puts African plant breeding at the head of the chain, with West African crops travelling thousands of kilometres through Arabian hands and changing what Indian farmers grew. Ehret's own summary is that historians have nearly everything still to learn here. A whole sphere of ancient exchange sat unexamined because the discipline had already settled that Africa contributed nothing to the connected world.

Two further West African crops travelled out of the continent, probably along the same sea routes and probably just as early. One was a tuber, Plectranthus rotundifolia, the country potato, which reached India, spread across southern Asia and eventually arrived in China. The other was Hibiscus sabdariffa, the roselle, which went further still. Its sharp leaves became a standard ingredient in sauces and soups in West Africa, in India and across Southeast Asia, and the fleshy sepals of its fruit are what hibiscus tea is made from. That drink now sells worldwide as a discovery of the wellness trade. West African farmers domesticated the plant, and African exchange networks carried it to the edge of every inhabited continent. These are crops that shaped what billions of people eat, and their origin has been rubbed out of the popular account so thoroughly that the people living off African plant breeding have no idea whose work they are living on.