Sweet potato
The sweet potato plant grows as a flowering vine with a large tuberous root. The root varies in color, ranging from white to orange to red to purple. Likely domesticated in South America, ancient Polynesians distributed it across the Pacific.
Later in the Fourth World, it spread further afield. As the globe warmed and the Fifth World dawned, people spread the tropics-adapted tuber well into polar regions. Because the tuber can grow well in many different kinds of soil, and adapts to extreme weather, it became a popular staple during the rapid climatic shifts around the time of collapse. It now flourishes all around the world, but rarely flowers in places that get less than 11 hours of sunlight.
#Human relations
People of the Fifth World enjoy the sweet potato tuber cooked in a wide variety of different ways: roasted, mashed, fried, and often mixed with a sweetener (such as honey) for a dessert. People also enjoy the young leaves and shoots as a nutritious vegetable.
People in South America often use red sweet potatoes and lime juice to dye cloth.
#Sweet Potato People
A community that specializes in relationship with sweet potatoes will invariably tend towards horticulture, and therefore live in settled villages at least part of the year. Often these communities practice swidden cultivation, growing different guilds of plants at different stages and moving around the jungle in a regular cycle. They likely grow sweet potatoes in traditional "banana circles" with banana, cassava, lemongrass, and taro.
A community specializing in relationship with sweet potatoes may have developed that relationship in response to the Rusting Age. During that time, warlords rose up in many places to fill the niche left empty by fallen states. A local warlord may have demanded tribute from this community and the others around it. In response, this community may have determined that growing tubers, rather than wheat or corn, could provide calories that the warlord’s tax collectors couldn’t see or collect as effectively. Long after a changing climate forced this community to practice more horticulture and less intensive agriculture, they may fondly remember how the sweet potato helped them hide their food stores from the warlord until his empire, too, collapsed.
A community specializing in relationship with sweet potatoes may trace its ancestry to the Pacific Islanders who originally domesticated and spread the tuber. Or they may trace descent from sweet potato-loving people who once lived in the American Southeast. During collapse, as a result of climate change, the American Southeast and many small islands in the Pacific flooded, scattering these places' inhabitants across the world. They may still tell stories of how their ancestors fled the floods, taking care to bring sweet potatoes with them to plant in their new homes. The sweet potato, as a staple tolerant of many different types of soil and which kept their ancestors alive in difficult times, will likely hold great importance to them.
Whether or not they descend from the seafaring Polynesians who initially spread the sweet potato across the Pacific, a community specializing in relationship with sweet potatoes may take to the sea as much as they did -- and will likely find the tuber useful to take with them when they do. Able to keep well and high in vitamin C, sweet potatoes help stave off scurvy for those people of the Fifth World who sail the open ocean. Such communities invariably trade different varieties of sweet potato with the people they meet on their travels, keeping their local stock of sweet potatoes genetically diverse.
Because sweet potatoes can grow in water, a community specializing in relationship with sweet potato may plant the tuber in ponds or on the banks of streams. The root systems will provide refuge for fish, whose waste products in turn feed the sweet potato. In this way, the community can ensure a steady supply of food from both sweet potatoes and local aquatic life.