This article presents the results of an anthropological and ethnobotanical study of the vegetable salts used by the Witoto Indians of the Amazon. It thoroughly documents the species used, the processing of the salts, their chemical composition and their anthropological, nutritional and medicinal relevance.Salts from 57 plant species known to the Witoto were processed using the same materials and techniques employed by the Indians: burning plant material, lixiviating the ashes with water, and boiling down the brine to desiccate the salt. Chemical analyses of macroelements of 49 of the salts, and of microelements of 24, were conducted. Tests on the taste of the salts as perceived by the native persons were carried out.Average ratio ashes/raw material was 3.05% (from 0.71% to 10.14%); average ratio dry salt/ashes was 11% (from 1% to 37%). All the samples analyzed presented a high proportion of potassium (26.9-44.6%); contents of phosphorus, sodium, calcium and magnesium were less than 1%; contents of carbonate, chloride and sulfate varied greatly among the salts. Boron, molybdenum and vanadium were present in all or almost all the samples analyzed; copper, barium and strontium were also frequent; manganese, zinc and iron were less frequent.There is a correlation between the concentration of the three anions and the perceived taste of the salts, the "sweet" flavor of chloride being the preferred taste. Our research shows that the culinary function of these salts is secondary to their ritual, medicinal and cosmological meaning. The search for chloride is one of the reasons to produce and consume these salts; other reasons are also important: their alkaline pH, which liberates the alkaloid of the tobacco with which the salts are mixed; and their contents of microelements, which, although not discernible in taste, are inferred from symbolic associations of the species used.