Did you know? – Sweet potato

SESL Australia
Close up of sweet potatoes, or kumara
Kumara in Maori, kumar in Quechua (Peru). Photo: Procsilas Moscas. Used under Creative Commons licence.

How did the sweet potato get from the Americas to the Pacific islands before the European explorers?

Sweet potato (Ipomoea batatas) originated in Mesoamerica, somewhere between the Yucatán Peninsula and Venezuela. It is a member of the morning glory family (Convolvulaceae). The shoots as well as the tubers are edible.

Archaeological evidence shows that the sweet potato was being eaten 8000 years ago and that it was being cultivated 5000 years ago throughout Mesoamerica, the Caribbean and South America.

The species name, batatas, comes from the Taíno language of the Caribbean, and gives us our word “potato”. Prehistoric trade within the Caribbean spread the sweet potato throughout the islands, where Spanish and Portuguese explorers encountered it. But when they started exploring the Pacific region, it had got there before them.

The famous 20th century explorer Thor Heyerdahl built his raft Kon-Tiki with the goal of proving that South Americans could have made long voyages. Right idea, wrong direction.

Evidence continues to mount that the ancient Polynesians – arguably the world’s greatest ancient mariners – reached South America and brought the sweet potato back with them. The Maori of New Zealand were subsisting on sweet potato when Lieutenant (later Captain) Cook arrived in 1769. Notably, the Maori word for sweet potato, kumara, is almost identical to the Quechua name, kumar, from Peru.

Using genetic techniques to trace the origin has been problematic, because the Europeans introduced sweet potato around the world, and subsequent interbreeding has masked the origins.

But a recent analysis of herbarium specimens by French researchers has revealed differences between eastern and western Pacific accessions, supporting the “tripartite” hypothesis that sweet potato was introduced into the Pacific in three waves: first by the ancient Polynesians, and later by the Spanish from Mexico and by the Portuguese from the Caribbean.

Further reading

Wade E. 2013. Clues to prehistoric human exploration found in sweet potato genome. Science Now.

Wikipedia. Sweet potato.