Epiphytic or epilithic grasslike plants. Fronds simple, linear, entire, glabrous. Venation consisting of a costa and oblique unbranched veins, free except for a submarginal fertile connecting vein. Sori in one elongate marginal or submarginal groove on each side of lamina, immersed, rarely superficial; paraphyses long with a dark obconic head. Spores monolete, most ellipsoid, sometimes fusiform, smooth, transparent.