Prehistoric cultures cultivated and domesticated diverse crops all over the world. Some of these ancient crops are still cultivated today, but many are not. The reasons some domesticated cultivars survived to present day while others went extinct is often a mystery.
At least five species were domesticated in prehistoric eastern North America: sunflowers, squash, goosefoot, erect knotweed, and marshelder. The domesticated forms of goosefoot, erect knotweed, and marshelder have been extinct for hundreds of years. These lost domesticated crops can tell us much about the lifeways of prehistoric peoples. As we learn more about these lost crops, we learn how to build increasingly resilient and sustainable food systems for people today.
Chenopodium berlandieri, often called goosefoot or lambsquarters, is the closes wild relative of the prehistoric domestic crop C. berlandieri subsp. jonesianum, a component of the initial cultigen complex in Eastern North America (ENA). It is close relative of the Andean pseudograin quinoa (C. quinoa) and shares many of its desirable qualities. The species has been domesticated twice in North America, once in ENA and separately in Mesoamerica. The Mesoamerican variety (C. berlandieri subsp. berlandieri) remains under cultivation by local populations to this day, while the ENA domesticate (C. berlandierisubsp. jonesianum) is known exclusively from the archaeological record.
Prior to domestication, C. berlandieri likely colonized disturbed riverbanks and land adjacent to habitation sites. Seeds from these opportunistic chenopods were likely harvested for food as early as 8,500 B.P. By 3800 B.P. archaeological findings show that C. berlandieri had the morphological signatures of domestication, indicating it was under continuous cultivation. The crop was widely grown throughout ENA as part of a food system that included a set of other indigenous crops and foraged food sources. C. berlandieri cultivation declined following the introduction of maize (Zea mays). The crop was no longer cultivated in ENA by approximately 1750 C.E. Although the domestic cultivar C. berlandieri subsp. jonesianuim is extinct today, its weed progenitor remains an eager colonizer of disturbed soil throughout the eastern United States.
- Kistler, L. & Shapiro, B. Ancient DNA confirms a local origin of domesticated chenopod in eastern North America. J. Archaeol. Sci.38, 3549–3554 (2011).
- Smith, B. D. Rivers of Change: Essays on Early Agriculture in Eastern North America. (University of Alabama Press, 2006).
- Patton, P. E. & Curran, S. Archaic Period Domesticated Plants in the Mid-Ohio Valley: Archaeobotanical Remains from the County Home Site (33at40), Southeastern Ohio. Midcont. J. Archaeol.41, 127–158 (2016).
Erect knotweed (Polygonum erectum) has been recently been identified as a prehistoric domestic crop, though there has long been evidence for its long-term cultivation and use as a preshitoric food source. Comparison of archaeobotanical samples to modern wild populations shows a clear difference in seed germination inhibition, a phenotypic marker of domestication. About 2,500 years of intentional planting and harvesting transformed the annual weed adapted to environmental uncertainty into an cultivar dependent on human care. The domestic variety (P. erectum ssp. watsoniae) is now extinct but wild stands are common.
- Mueller, N. G. Documenting domestication in a lost crop (Polygonum erectum L.): evolutionary bet-hedgers under cultivation. Veg. Hist. Archaeobot. 1–15 (2016). doi:10.1007/s00334-016-0592-9
As long ago as 8000 years B.P. wild marshelder (Iva annua var. macrocarpa) was widely harvested across the eastern United States and became part of the initial crop complex (ICC). Seeds recovered from an archaeological site in Illinois had 31% enlarged achenes compared with wild populations, a morphological indication of domestication. The earliest known sample of domesticated marshelder seeds dated to ca. 3,920 years B.P. This cultigen is often treated in literature as a minor crop; however, the temporal association with the other crops of the initial crop complex in Eastern North America suggests that it was important as a component of a diverse food base.
Marshelder is presently found in wild stands throughout much of the eastern and central United States and southward into Mexico. With one exception, all known populations produce the small seeds of a weedy crop rather than a those associated with domestication. Research into domestication of Iva annua and traits associated with domestication of the crop are ongoing.
- Asch, D. & Asch, N. in Prehistoric Food Production In North America (ed. Ford, R. I.) 149–203 (University of Michigan, 1985).Smith, B. D. Eastern North America as an independent center of plant domestication. Proc. Natl. Acad. Sci. U. S. A.103, 12223–12228 (2006).