Etymology Greek: kyrtoma means arch. The veins rejoin forming an arch.

Description Rhizome: erect, large tan scales.
Frond: evergreen, monomorphic.
Stipe: scaly, vascular bundles: 4 or more, in an arc.
Blade: 1-pinnate, oblong-lanceolate; the blade is terminated by a pinna similar to the others, a characteristic called imparipinnate, leathery, filiform scales below, glabrous above.
Pinnae: holly-like, distal pinnae only slightly smaller, costae grooves above continuous from rachis to costae, segments crenate to spinulose, veins netted.
Sori: round, in 2 or more rows between midrib and margin, indusium: peltate, persistent or not, central, sporangia: brown.

Distinctive Characteristics shares the peltate indusium with Polystichum as well as, in some cases, an upward ear at the base of the pinnae; differs in a terminal pinna similar to the lateral ones; it shares the grooves continuous from rachis to costae with Dryopteris, and it differs from both in the net veining.