Erect perennials with creeping, scaly rhizome. Leaves long-petioled, of two forms: sterile and fertile, or lower segments sterile and upper fertile; blade 1-4-pinnate; veins free or anastomosing. Sori linear, continuous along margin of segments; indusium (pseudo-indusium) linear, continuous, formed of the reflexed margin of segments, more or less covering the sori.