Caudex massive, prostrate or erect, the young parts covered with hairs. Stipes long in proportion to lamina, more or less hairy throughout; pneumathodes prominent and separate (subg. Culcita) or forming a not quite continuous line along each side (subg. Calochlaena, Fig. 34d). Lamina of large fronds quadripin-nate, deltoid, pinnae and pinnules also deltoid, all branches of the frond asymmetric at the base, acroscopic sub-branch longer and at a broader angle than basiscopic; all axes and midribs of leaflets grooved on adaxial surface, the groove on a larger axis open to admit grooves of smaller ones borne upon it (Fig. 34c). Sori at the ends of veins, receptacle elongate at right angles to the vein-end, protected by a small reflexed lobe of the lamina (the outer indusium) and by a thinner inner indusium attached to the base of the receptacle; sporangia about as in Dicksonia, accompanied by many hair-like paraphyses; spores trilete, outer surface verrucose (Malaysian species).
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