Ancient fire regimes have been a key element in terrestrial ecosystems, and their influence on the evolution of fire-related traits spans many millions of years. We classified 115 South American ecoregions into three major Pyromes (areas with similar wildfire regimes) and identified key plant fire-related traits. The "Rare" Pyrome included rainforests and deserts where natural fires are unusual, and most species are fire-sensitive. The "Intense" Pyrome was characterized by infrequent high intensity fires associated with high interannual rainfall variability and anthropogenic activity, occurring in seasonal tropical/temperate forests and semi-arid shrublands, where post-fire regeneration generally occurs via basal resprouting or reseeding. The "Frequent" Pyrome comprised mostly tropical grasslands and savannas experiencing regular and frequent fires. Fire-related traits such as thick/corky bark, resprouting from underground organs and aerial bud banks, as well as fire induced flowering, are commonly found in the Frequent Pyrome. Plant traits evolved over millions of years in response to particular fire regimes. However, modern fire regimes are increasingly affected by human influence, with negative consequences for species and ecosystems. We advocate that the legacy of ancient fire regimes on the evolution of the South America ecosystems should be considered to keep them biologically and functionally diverse.