SORI are compact, and borne on the lower surface of leaves. Sessile, or joined in a massive, indurated synangium, they lack an annulus. They are either monolete or trilete. They are unbranched, and range from moderately stout to massive.
Stems are fleshy, with sometimes persistent scales.
Very sparingly to moderately scaly, especially on the axes, they are circinate in bud. Leaves range from 50 cm to over 3 m in length. At least somewhat elongate, it is centrally thickened and sometimes branched. Archegonia are borne centrally on the lower surface. Antheridia are borne mostly on the lower surface, but may be found on the upper surface, or even on the margins.