Sweet potatoes

Sweet potato is not closely related to the common potato, and it is also distinct from true yams. It belongs to the morning-glory family, Convolvulaceae, and grows as a trailing tropical vine with enlarged storage roots. Its exact domestication story is still being refined, but botanical, archaeological, and genetic evidence places its development in the tropical Americas, most likely between Central America and northwestern South America.

Indigenous farmers transformed ancestral vines into a remarkably diverse crop. Over thousands of years, they selected sweet potatoes with roots that differed in size, sweetness, texture, skin color, and flesh color. Archaeological remains show that cultivated sweet potatoes were present in South America several millennia ago, long before European contact.

Sweet potatoes also reached Polynesia before sustained European exploration of the Pacific. Their pre-contact presence there is widely accepted, although scholars continue to investigate the timing and human routes behind that movement. After the 15th century, Spanish and Portuguese trade carried the crop more broadly through Europe, Africa, and Asia, where it became especially valuable because it could produce substantial food in warm climates and varied soils.

Today, sweet potatoes are major foods across Africa, Asia, Oceania, and the Americas. China is the largest producer, while North Carolina leads commercial production in the United States and California is another important growing state. Modern varieties range from dry, pale-fleshed roots to moist orange types and deeply colored purple sweet potatoes—all descendants of a crop first shaped by Indigenous agriculture in the Americas.