Giulia Caneva, of the Department of Biology of the University of Roma Tre, is carrying out a taxonomical and interpretative study of the vegetal species represented on the Ara Pacis, both n the larger frieze and in the festoons of the internal precinct. More than fifty species have been identified so far. They are represented in a pattern that, due to its occurences and symmetry, becomes highly meaningful. The iconographic programme of the Ara Pacis depends on a careful observation of nature, and draws its main inspiration from the vegetation of rocks and garrigues, as well as from ruderal areas typical of the Mediterranean pastoral environment. This image of nature, seen in its most flourishing moment of growth and bloom, would reveal a symbolic implication related to rebirth and would imply a non-anthitetical relationship between unity and multiplicity, together with the idea of infinitum, that is of a potential eternity.