Gladiolus or 'sword lily' is a flowering plant that grows from corms, or small tubers. Native to Asia, southern (Mediterranean) Europe, and tropical areas of Africa, today they are highly prized as ornamental plants. Extensive hybridization has led to a rainbow of colors among gladioli. One species of moth, the Large Yellow Underwing (Noctua pronuba), relies heavily upon gladiolus as a food source for its larvae.