Plants terrestrial; rhizomes massive, creeping to ascending or erect (up to 6 m), solenostelic or sometimes dictyostelic with vascular bundles lacking sclerenchymatous sheath, bearing adventitious roots, densely covered with soft, yellowish brown, multicellular long hairs at apices and persistent stipe bases. Fronds approximate, forming a crown at apex, monomorphic or dimorphic, mostly 2-4 m; stipe hairy at base, with 3 corrugated vascular bundles (1 abaxial, 2 adaxial) arranged in an omega-shape with adaxial ends curved strongly inward, or with abundant V-, U-, or W-shaped vascular bundles arranged in omega configuration, sometimes adaxial inwardly recurved arms of vascular bundles forming an isolated set of bundles in a reversed U-shape; stipe flattened on adaxial face with lateral aerophores (pneumatophores) forming a line on each side; lamina 2-pinnate + pinnatifid to 3-pinnate + pinnatifid, firm, often glaucous abaxially, glabrous when mature or persistently hairy on rachis, costa, costules, and veins; rachis hairy in middle, in dried material often sulcate in middle of ridge, which is flanked by 2 grooves; sterile segments entire or crenate; fertile segments poorly differentiated; veins free, simple or forked to pinnate; stomata paracytic with 3 subsidiary cells. Sori single, marginal at vein ends, indusiate; indusia bivalvate, each with a strongly differentiated, non-green outer indusium and a similarly modified tonguelike inner indusium; paraphyses few, short and brown; spores globose-tetrahedral, with prominent angles and a well-developed equatorial flange; antheridial walls 5-celled. x = 68.
Home