A blade of grass with a serrated edge (Paspalum sp), coloured scanning electron micrograph (SEM). Plants evolve specialized physical and chemical characteristics in natural defence against stresses in their environments. The sharp saw-toothed edge of a blade of grass protects against herbivores. Paspalum is a genus of plants in the grass family Poaceae. This grass group is widespread across much of Asia, Africa, Australia, and the Americas Commonly (eg. paspalum, bahiagrasses, crowngrasses and dallis grasses). They are usually are tall perennial New World grasses. They are warm season grasses (C4) and are most diverse in subtropical and tropical regions. Magnification: x50 when shortest axis printed at 25 millimetres.