A general term for a genus of grasses of which the most important species is the deeply rooted perennial Paspalum dilatatum. Dallis grass is widely used in the southern United States, mostly for pasture, and remains productive indefinitely if well managed. Dallis grass does best on fertile soils and responds to lime and fertilizer. On heavier soils it remains green throughout the winter unless checked by heavy frosts. Seed production is hampered by infection with ergot, a fungus that invades developing seeds and produces purplish-black horny bodies. Ergot-bearing seed heads are very toxic to livestock, whether in pasture or in hay, and Dallis grass must be so managed as to prevent consumption of infected heads by livestock.