Roots proliferous. Stems erect, unbranched; scales brown throughout, narrowly lanceolate, 5--10 × 1--1.5 mm, margins entire. Leaves monomorphic. Petiole vestigial. Blade linear, oblanceolate, simple, (10--)20--40(--70) × 3--8 cm, thick, glabrous; base gradually tapered; margins entire to irregularly crenate; apex attenuate, not rooting. Rachis green throughout, dull, glabrous. Veins numerous, free, mostly immersed. Sori parallel to each other, nearly perpendicular to midrib. Spores 64 per sporangium. 2 n = 144.