Stems ascending to erect. Leaves erect to arching back at tip, 2--8 dm; bulblets absent. Petiole 1/4--1/3 length of leaf; scales abruptly diminishing in size distally and falling off early but retaining conspicuous tuft of brown scales at base. Blade linear-lanceolate to linear, 1-pinnate, base not or slightly narrowed. Pinnae oblong, slenderly lanceolate, or falcate, usually overlapping, in 1 plane or twisted out of plane of blade, 2--4 cm; base oblique, auricles well developed; margins serrulate-spiny with teeth ascending; apex cuspidate or apiculate with subapical teeth smaller than apical tooth; microscales lanceolate to linear with straight or sharply angular projections, sparse, on abaxial surface only. Indusia entire to sharply dentate. Spores dark brown. Polystichum imbricans is one of the postulated ancestors of two allopolyploids, P . californicum and P . scopulinum (D. H. Wagner 1979). Relationships to P . munitum are discussed under that species.