@article {2472,
	title = {Documenting domestication in a lost crop (Polygonum erectum L.): evolutionary bet-hedgers under cultivation},
	journal = {Vegetation History and Archaeobotany},
	volume = {2621544151612277251256252491314471317501927512453130187936325211846611242525023108578256126282112},
	year = {2017},
	month = {Jan-05-2017},
	pages = {313 - 327},
	abstract = {This study uses morphometrics and digital image analysis to document domestication syndrome in an annual seed crop, Polygonum erectum L. (erect knotweed), which was cultivated by Native Americans for c. 2,500 years in eastern North America. This plant is one of several seed crops referred to as the Eastern Agricultural Complex, a pre-maize agricultural system that supported societies in a core area centred on the central Mississippi valley for millennia. The extinct domesticated subspecies P. erectum ssp. watsoniae N. G. Muell. described here, exhibits some classic markers of domestication, including larger fruits and reduced germination inhibitors in comparison to its wild progenitor. Domesticated P. erectum also exhibits greatly reduced germination heteromorphism. Germination heteromorphism is the classic example of evolutionary bet-hedging in plants: wild P. erectum sacrifices maximum fitness per generation for a reduction in fitness variance over many generations. It does so by producing two different types of fruits: ones that germinate immediately in the spring after they are produced (smooth morphs), and ones that remain in the soil seed bank for one or more growing seasons before germinating (tubercled morphs). Tubercled morphs allow populations to recover after adverse events. Under cultivation, the selective pressures that maintained this strategy were relaxed as humans saved seeds and created predictable microenvironments for seedlings, resulting in homogenous harvests and reliable germination for ancient farmers.},
	keywords = {Domestication, Eastern Agricultural Complex, Evolutionary bet-hedging, Morphometrics, Origins of agriculture},
	issn = {0939-6314},
	doi = {10.1007/s00334-016-0592-9},
	url = {http://link.springer.com/10.1007/s00334-016-0592-9http://link.springer.com/content/pdf/10.1007/s00334-016-0592-9.pdfhttp://link.springer.com/content/pdf/10.1007/s00334-016-0592-9.pdfhttp://link.springer.com/article/10.1007/s00334-016-0592-9/fulltext.html},
	author = {Mueller, Natalie G.}
}
@article {2473,
	title = {An Extinct Domesticated Subspecies of Erect Knotweed in Eastern North America: <i>Polygonum erectum</i>               subsp. <i>watsoniae</i>               (Polygonaceae)},
	journal = {Novon: A Journal for Botanical Nomenclature},
	volume = {25},
	year = {2017},
	month = {Jan-04-2018},
	pages = {166 - 179},
	abstract = {This paper provides a description of an extinct domesticated subspecies of erect knotweed (Polygonum erectum L.). Masses of erect knotweed achenes are often recovered from archaeological sites in eastern North America dating to ca. 3000{\textendash}600 BP. Several paleoethnobotanical assemblages from the later part of this era (ca. 1000{\textendash}600 BP) contain achenes that are outside the range of natural variation for erect knotweed. The most well preserved of these archaeological assemblages, a desiccated cache of achenes from the Whitney Bluff site, Arkansas (ca. 900 BP), is compared to four closely related species and subspecies of Polygonum L. The Whitney Bluff achenes are most similar to those of P. erectum, but differ from modern fruits of this species in three respects: (1) fruits are larger, (2) average pericarp thickness is reduced, and (3) fruit dimorphism is greatly reduced. These differences are typical of domestication syndrome in annual seed crops. The Whitney Bluff assemblage is described as the type specimen of a domesticated subspecies, P. erectum subsp. watsoniae N. G. Muell.},
	keywords = {Domestication, Eastern Agricultural Complex, fruit morphology, paleoethnobotany, Polygonum},
	issn = {1055-3177},
	doi = {10.3417/2016005},
	url = {http://www.bioone.org/doi/10.3417/2016005http://www.bioone.org/doi/full-xml/10.3417/2016005},
	author = {Mueller, Natalie G.}
}
