Aquatic or semi-aquatic fern; rooted or free floating plants that complete their life cycle in a vry short time. Rhizome short erect; roots few arising from near the stipe base, with scales. Stipes green, succulent. Fronds tufted, dimorphic: fertile fronds larger, more dissected and with narrower linear segments than the sterile fronds; the fertile fronds often proliferous. Lamina pinnately compound, hebaceous, glabrous; venation forming a network, without included veinlets. Sporangia borne on the ultimate segments, solitary along the veins, within the reflexed margins.