Fern with creeping subterranean rhizome bearing widely spaced, stiff, erect, pubescent fronds, 0.5-1.75 m tall, often forming large, dominant colonies in suitable habitats. Underground portion of the stipe swollen. Lamina 3-pinnatifid to 4-pinnate, triangular in outline. Pinnae standing out from the rhachis horizontally at nearly right angles. Basal pinnae half as long as the frond; pinnae in the upper half 3-pinnatifid. Pinnules deeply incised, adnate to the costules, with apices that are not long and narrow. Sori linear, borne along the entire margins of the pinnules.