Endemic

Greek kyrtos, curved,+ theke, case, sheath, supposedly in reference to the indusium being bent out of the plane of the blade.

Plants small to medium-sized, terrestrial. Rhizomes climbing, 1.5-2 mm diam. Fronds 13-37 x 8-12 cm. Stipes long, usually 1/3-1/2 frond length, fine dark hairs at bases. Blades 2-to 3-pinnate, triangular, widest at bases, dark green, stiff-membranous, glabrous, in living plants blades often incline at 45° angle to stipe. Pinnae lanceolate, tips acuminate. Ultimate segments deeply lobed, lobe tips dentate. Veins free, forked, prominent. Sori marginal, arising in sinuses, usually on short, bent stalks, commonly oriented at right angle to blade, often absent. Indusia narrowly cone-shaped, tips slightly flared. Common terrestrial, often climbing on rocks and tree trunks in gulch bottoms or in dark, wet forests, 150-750 m, all major islands.

Vandenboschia cyrtotheca may be recognized by its usually long stipes, trianular fronds with basal pinnae as large as or larger than the more distal pinnae, and sori oriented at right angles to the blades. When seen on live plants, the blade is often bent backward at a 45° angle to the stipe.