Plants terrestrial, large to very large, less often medium-sized, with short to usually long, erect, slender to robust, apically scaly stem. Stems with dictyosteles, apices (and usually stipe bases) covered with large scales, sometimes also with small scales or hairs. Fronds usually large (up to 5 m); stipe with obvious, usually discontinuous pneumathodes in two lines; lamina 1-3-pinnate (rarely simple); veins simple to forked, free, rarely anastomosing. Sori superficial (abaxial) or terminal on veins and marginal or submarginal, orbicular, exindusiate, or indusia saucerlike, cuplike, or globose and completely surrounding sporangia, or bivalvate; sporangia maturing gradually, with oblique annuli; receptacles raised; paraphyses usually present; spores tetrahedral, trilete, variously ornamented; gametophytes green, cordate. x = 69.
Stems clothed with persistent leaf–bases and matted adventitious roots; scales present at the apex of the stem and bases of the stipe; fronds large, bipinnate, usually spiny at base, arranged spirally at the apex of the stem
Tree ferns, with (in W.African species) stout erect dictyostelic trunks
Erect ferns with stems (trunk or caudex) to 10 m in Africa; rarely (not in Africa) prostrate or epiphytic; vascular tissue forming a hollow cylinder perforated by large gaps, the surface of stems covered with densely matted adventitious roots, rarely spiny; stipe bases persistent or, if not, then stipe scars prominent, old fronds rarely clothing the stem