After William Brewer (1828-1910), a California collector and an author (with Sereno Watson and Asa Gray)of the first flora of California.
Rhizome: short-creeping or erect, scales uniformly reddish brown, linear.
Frond: 20 cm high by 4 cm wide, evergreen, monomorphic, blade/stipe ratio: 3:1.
Stipe: brown, shiny, extending through most of the rachis, rounded above, prominent articulation lines near the base, croziers sparsely hairy at emergence, then glabrous, vascular bundles: 1.
Blade: 1-pinnate-pinnatifid, barely so, linear, leathery, rachis glabrous.
Pinnae: 6 to 10 pair, bluish-green, sessile, a terminal pinna like the upper lateral ones; margins entire; veins free.
Sori: oblong or linearly joined, submarginal, indusium: false, inrolled margins, sporangia: pale brown, maturity: summer to fall.
Habitat: cliffs and rocky slopes.
Distribution: western North America, California to Washington to Colorado at moderate to higher elevations, rare.
Hardy to -25°C, USDA Zone 5.
The joints near the base of the stipe are diagnostic, confirmed with the 1-pinnate-pinnatifid division.