Vilca, an encounter of approaches: Antecedents and tools for its search in archaeological contexts in the south central Andes

Abstract

Ethnohistoric and ethnographic studies in the south-central Andes use the term vilca to name the species Anadenanthera colubrina var. cebil; however, ethnographical studies in northern Chile detected the use of the term to name a similar legume, Acacia visco. This created a confusion between both species, because it has been reported that A. colubrina var. cebil grows in Chile, mistaking it with A. visco and misleading the interpretation in relation to its significance as a foreign source coming from the east of the Andes. Remains of A. colubrina var. cebil have been archaeologically found in domestic, funerary and ceremonial contexts in northern Chile and northwestern Argentina, meanwhile A. visco is rarely mentioned in archaeological reports. The broad similarity of the seeds of these two species, and the absence of reports dealing with characteristics that may be used to distinguish them in archaeological contexts prompted the present comparative study. This work addresses the geographic distribution of both species and the archaeological evidence of their use, and characterizes their seeds using archaeobotanical and chemical methodologies. The analysis of microfossils showed new diagnostic morphotypes of histological elements different from those already described, and chemical analyses showed the presence of bufotenine in the seeds of both species in widely differing concentrations. These findings provide new archaeobotanical and chemical markers to distinguish between the two species in samples from archaeological contexts.