Ancient use of the four corners potato

Despite its long history, utilitarian value, and cultural significance to
several Indigenous Tribes in the Southwest USA, the extent to which the
Four Corners potato (Solanum jamesii Torr.) has been domesticated requires
circumscription. Establishing the temporal and spatial dimensions of
intentional cultivation would provide an essential component of the
domestication argument. This project tests the hypothesis that S. jamesii
tubers were processed with ground stone tools from archaeological sites
located beyond the natural range of the species, especially where genetic
evidence has previously indicated human transport and establishment in
gardens. Microbotanical evidence, in the form of starch granules from 401
ground stone tools at 14 archaeological sites, is examined. More than
6,500 starch granules were recovered from the tools; 163 of which were
assigned to S. jamesii.  Four sites (North Creek Shelter, Long
House/Mesa Verde, Pueblo Bonito/Chaco Canyon, and Point of Pines) show
consistent use of S. jamesii (ubiquity >18%), as early as 10,900
cal BP, and well into Puebloan times.  Three of these sites are
located far north of the species’ center of distribution in the Mogollon
region, across hundreds of kilometers of the Colorado Plateau, and still
support an extant population nearby. This suggests an anthropogenic
distribution of S. jamesii across the Four Corners region and a unique
cultural identity around the use of this native potato.  These
findings, combined with ethnographic interviews and nutritional data,
provide clear evidence of use in relation to natural and anthropogenic
distributions, thereby allowing an assessment of the degree to which these
energy-rich, nutritious, and compact tubers were purposely used and
transported.