The Ayoreo, an Amerindian group of the Paraguayan Chaco, use ash from several plant species as sources of salt. The elemental composition of the ash ofMaytenus vitis-idaea, Lycium nodosum, Trithrinax schizophylla and another sample which serve as salt sources are reported and the use of vegetal salts by indigenous South American populations is discussed. The relatively high sodium content ofM. vitis-idaea may explain the widespread use of this species as a salt source by Chaco Amerindians.