Many native tribes in North America use sweetgrass in praying, smudging or purifying ceremonies and consider it a sacred plant.  It is usually braided, dried, and burned.  Sweetgrass braids smolder and don't produce an open flame when burned.  Just as the sweet scent of this natural grass is attractive and pleasing to people, so is it attractive to good spirits.  It is often burned at the beginning of a prayer or ceremony to attract positive energies.  Source:  Native Tech