Plants terrestrial or on rock. Stems erect or creeping, branched; scales pale brown to black, concolored, elongate, margins entire. Leaves monomorphic, clustered or closely spaced, 1--20 dm. Petiole straw-colored, green, brownish red to purple black, longitudinally ridged, 2--3-grooved adaxially, scaly at base, glabrous or scaly distally, with 1 (less often 2 or more) vascular bundle. Blade oblong to lanceolate to deltate, 1--4-pinnate, herbaceous to leathery, abaxially and adaxially glabrous or sometimes pubescent or scaly, adaxially dull, not striate; rachis straight. Ultimate segments of blade sessile to short-stalked, linear to oblong-lanceolate, 1.5--8 mm wide; base truncate or narrowed to stalk, stalk when present green, not lustrous; margins plane or reflexed to form false indusia. Veins in leaves conspicuous, free (except in sori) and forking well above base of segment, or highly anastomosing. False indusia pale, scarious, covering sori. Sporangia intramarginal, sori usually continuous except at pinna or segment apex and sinuses, paraphyses present. Spores brown, trilete, tetrahedral, rugate and/or tuberculate, usually with prominent equatorial flange. x = 29.

Petiole coarse, scaly, with 2 curved bundles at the base; lvs entire; veins pinnate, free, twice forked, ending short of the margin in linear hydathodes; sori linear, paired, one on the anterior branch of a vein, the other on the posterior branch of the next higher vein, the membranous, entire indusia facing each other and overlapping when young; evergreen terrestrial ferns with erect scaly rhizomes and numerous firm, glossy green, elongate, simple lvs. 8, widespread.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

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