Rhizome creeping, often deeply buried, covered with coarse, pale brown, narrow scales having long hair-points. Fronds close together or distant, unbranched (very rarely bifid), 10–40 cm long, dimorphic with fertile fronds erect and longer than the more spreading sterile fronds. Stipe length variable, 5–25 cm long in sterile fronds, slender, brittle, red-brown to almost black, shiny. Lamina linear, once pinnate, glabrous. Pinnules shortly stalked, asymmetrically wedge-shaped to fan-shaped, up to 1 cm wide, usually wider than long; outer margin wavy, crenulate, toothed or lobed; veins radiating out from base; pinnules in fertile fronds obliquely deflexed. Sori extending along outer margin, protected by membranous indusium with frilled margin.