Mueller believes that the Hopewell shared their seeds throughout many communities where people tended farms along the skein of rivers that connect the American South with the Midwest. But it also seems likely that the erect knotweed was domesticated at least twice: once in the Kentucky region where she found her sample, and once about a thousand years later in Illinois when the great pyramid city of Cahokia stood at the center of the Mississippian culture.
Many of these early farmers appear to have counted crops among their greatest creations. Crops were valued trade goods and shared with allies in the same way jewelry, projectile points, and fine pottery were. And, of course, they were placed in graves alongside other precious funeral goods. Farming was a science and key to survival, but it was also an art. Food and feasting were central to indigenous cultures in the Americas, just as they were to civilizations in Europe and Asia. Serving guests a delightful meal with many kinds of grains, breads, and oils would have been a source of pride and pleasure.
Losing a crop
Perhaps the strangest part of this story is the fact that people simply stopped cultivating so many crops that were central to their diets. Imagine what would happen if we decided to abandon wheat to the wilderness. Suddenly, there would be no more baguettes and pastas—not to mention cakes. Sure, we could make delicious breads from corn and tasty noodles from rice or beans. But for many of us, it would feel like an incredible loss of a comforting staple. No doubt, that’s how the loss of knotweed felt to aboriginal Americans, too.
It’s likely that the Eastern Agricultural Complex (EAC)—a catch-all term for the lost crops of North America—faded away slowly. Though we can't be sure what triggered its decline, Mueller thinks it may have suffered its first blow from one of the most popular crops in the Americas: maize, which came north from Mexico about a millennium ago.
“Maize is an amazing crop,” Mueller said. “All over the world, when it arrives, people give up their old crops and start growing it. It’s productive and has lots of sugar so it gives you quick energy.” By the time Cahokia was at its height in the 1000s, maize was already edging out crops like erect knotweed.
But the death knell for erect knotweed probably came from Europe. Archaeologists find no more examples of domesticated erect knotweed after colonists began to settle the Americas in the 1400s, destroying local civilizations as they went. “There was so much displacement, disease, and warfare over the next couple hundred years that a lot of knowledge was lost,” Mueller explained.