Submerged rock pavement (here) would have allowed the indigenous population to determine how far their tubers grew, thereby making it easier to harvest. (Credit: Katzie Development Limited nership)
This harvest was 3,000 years too late.
Hundreds of black potatoes were pulled out of the ground in a prehistoric garden in British Columbia, Canada.
Dating back to 3,800 years before the present, the garden was once under water, in an ecologically rich wetland. And it shows signs of advanced techniques used to the flow of the water to more efficiently grow in the wild wapato tubers, also known as Indian potatoes. [The 25 Most Mysterious Archaeological Finds on Earth]
Archaeologists led by Tanja Hoffmann of the Katzie Development Limited nership and the Simon Fraser University in British Columbia discovered the garden during road works on the Katzie First Nation area just east of Vancouver, near the Fraser River.
The site was waterlogged for centuries, resulting in a good preservation of plants and other organic materials, such as wooden tools that normally would be dissolved in time.
The researchers counted 3,767 whole and fragmented wapato plant (Sagittaria latifolia). Today, these plants are found in wetland areas in southern Canada and the United States. Although they were not domesticated, the chestnut-sized roots have long been important for the indigenous population, and they are mentioned in some of the first ethnographic accounts of the Pacific Northwest. Explorers Meriwether Lewis and William Clark, for example, were offered wapato roots in an indigenous village in the near present-day Portland, Oregon. Clark wrote in his journal that the plant resembled a “small Irish potato,” and after roasted, had “a pleasant taste and answers very well in place of bread.”
The old tubers that were found in British Columbia had dark brown to black in color, and some still had their starchy inside has been preserved.
The garden was covered with tightly packed, uniform-sized rocks, lead the researchers to the conclusion that this is a man-made deposit. Wapato plants can grow far under the ground, but an artificial rock “pavement” would have checked how deep the roots can penetrate. So would the harvesters to more easily find the tubers and then pull them from the muck, Hoffmann and her colleagues wrote in their study, published Dec. 21 in the journal Science Advances.
In addition to these swampy grounds, the archaeological site also had a dry area where people would have lived. The researchers also found about 150 wooden instruments that would be used to dig out the plants.
Radiocarbon dates from the burnt wood found at the site suggest that it dates back to 3,800 years ago and was abandoned from 3200 years ago.
The site, which may constitute the first direct evidence of wetland plant cultivation in the prehistoric Pacific Northwest, according to the report of this discovery.
Original article on Live Science.