Sweet potato; Ipomoea batatas

Contrary to what the name suggests, sweet potatoes are only distantly related to potatoes. While potatoes belong to the nightshade family, sweet potatoes belong to the bindweed family. Incidentally, their leaves are not only edible but also taste delicious. They are used as a vegetable in many cultures.

A portrait of the sweet potato plant

The sweet potato (Ipomoea batatas) belongs to the bindweed family (Convolvulaceae, morning glory). It is a perennial plant that is usually grown as an annual crop. Its shoots are creeping and can grow several meters long. The heart-shaped leaves vary in shape and colour depending on the variety.

The edible tubers are storage organs that develop underground. Depending on the variety, they can be orange, purple, white or yellow and grow up to 30 cm long. The flowers are similar to those of other bindweed plants. The plant thrives best in warm, tropical or subtropical climates – its optimum growing conditions start at temperatures from 24 degrees Celsius. If the temperature drops below 10 degrees Celsius, growth is severely restricted and frost kills the sweet potato. It likes water-permeable soil, which is why the sweet potato is often planted on mounds or earth banks.

The great mystery of the sweet potato

The sweet potato has a fascinating history that spans continents and cultures. For a long time, the theory was that it originated in the tropical regions of Central and South America, where it was cultivated over 5,000 years ago by indigenous cultures such as the Incas and the Maya. Archaeological finds in Peru and the Caribbean prove its importance as a staple food in pre-Columbian civilizations. In addition to its culinary role, it was also valued here for religious ceremonies and as a marketable good.

It was assumed that the sweet potato was brought to Asia by Polynesian seafarers before the Europeans occupied the Americas. However, in recent years new research has led to a new theory: A 57-million-year-old fossil of a bindweed, which includes the sweet potato, was discovered in the East Indies. The ancestors of the sweet potato probably originated here – though how the sweet potato spread and reached South America has not yet been clarified.

However, researchers agree that the sweet potato was introduced to Europe by European colonialists in the 15th century, where it was initially regarded as an exotic delicacy. Portuguese traders played a central role in the further spread of the plant. They also introduced the sweet potato to their colonies in Africa and Asia. The plant quickly spread, particularly in the coastal regions of Africa, as it thrived in tropical climates and was a solid addition to existing agricultural systems.

The sweet potato was also introduced to China in the 16th century and quickly gained importance, especially in times of food shortages. Due to its ability to grow on marginal soils, it became an invaluable food crop in rural areas. Today, China is the world’s largest producer of sweet potatoes.

About the name ‘sweet potato’

The Portuguese name batata-doce (literally ‘sweet potato’) influenced the name of the plant in various parts of the world. This illustrates the linguistic and cultural footprint left by the Portuguese colonial period. Even in regions where other languages dominate, variations of the Portuguese name are recognisable in the local names of the sweet potato.

Delicious and healthy!

The sweet potato is mainly eaten as a vegetable. The root fruit is eaten baked, boiled, deep-fried or mashed. It is used in soups, desserts, snacks and main dishes. It is rich in beta-carotene (vitamin A), potassium and fibre. 100 grams of sweet potato cover almost the entire daily requirement of vitamin A and beta-carotene. In particular the orange and purple varieties are known for their antioxidant properties.

The leaves can also be eaten. In Zambia, for example, the dish kalembula, sweet potato leaves fried with onions and tomatoes, is widespread. Some farmers also use the leaves as feed for their animals.

Sources

International Potato Center. Link.
Spiegel Online: But not from America. Researchers crack sweet potato riddle. Link.
Just Taste: The history of the sweet potato. Link.
FAO: Reports on the global distribution and historical importance of the sweet potato