Aquatic or semi-aquatic fern; rooted or free floating plants that complete their life cycle in a very short time. Rhizome short, erect or creeping; roots few arising from near the stipe base, with scales. Stipes green, succulent. Fronds numerous, tufted, dimorphic, sometimes proliferous, pinnate or 2- or 3-pinnatifid, herbaceous, glabrous, venation forming a network. Sporangia borne on the ultimate segments; solitary along the veins, within the reflexed margins or covering the lower surface of the fertile lamina with the margin not modified or reflexed; homosporous. Worldwide: 2 genera, c. 7 species worldwide Caprivi: 1 genus and 1 taxon. |
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