Sweet potato vine: a well-travelled food

My tenants are Congolese and they asked me if they could cultivate a small vegetable patch to grow edible plants from their country that are not readily available here in South Africa. I agreed, but I warned them that they may have problems growing vegetables that thrive in Central Africa in our colder, more arid climate. After a few failed tries, we finally found a spot in the garden where the plants grew well: sunny and warm but only getting full morning sun. They told me that the vegetable in question is called matembele in Lingala, the Congolese language that they speak. It has started flowering and now I have been able to identify the plant.

The flowers show that it is Ipomoea Batatas, a family of plants which includes sweet potatoes and morning glory vines. So how did sweet potato vines, native to South America, end up becoming a vegetable of tropical Africa? The answer to that must lie with the early Portuguese explorers and traders, who were the first to make any significant exploration of the coastline of Africa. There was already substantial Spanish conquest of South America, which introduced many new plants to the world. While people think of West Africa as the most significant contributor to slavery in the Americas, many slaves were of Congolese origin and the majority of these unfortunate people were taken to Brazil, a Portuguese colony at the time.

Sweet potato vine is a tasty leafy vegetable when cooked in a traditional African way: The leaves are chopped finely and cooked together with tomatoes, onions, chillies, salt and oil. Congolese people also add fish to the pot, making a nutritious meal that is often eaten together with Cassava, another plant native to South America that features strongly in West and Central African cooking