[2] The fronds grow 6–10 in (15–25 cm) tall,[3] and are fan-shaped, light to medium green with dark brown to black stems.

New fronds unfurl from a tight coil (circinate vernation) held on a tall stalk.

Oblong sori (masses of spores) form beneath a curled-under leaflet edge (false indusium).

[7] When growing on sunny serpentine talus and bedrock, the fronds are held vertically, giving the fern a rather different general appearance.

[8] The species[9] and its cultivar 'Subpumilum' have gained the Royal Horticultural Society's Award of Garden Merit.