Etymology After Walter Birney Anderson (c1856-1944), collector and Government Inspector of Indian orchards. Collected August 2, 1912 on Vancouver Island, British Columbia.

Description Rhizome: erect, forms a trunk, trunk clothed in roots.
Frond: 100 cm high by 20 cm wide, evergreen, monomorphic, blade/stipe ratio: 3:1 to 7:1.
Stipe: green, grooved, scales dense, light brown, diminishing in size upwards, vascular bundles: 4 or more, in an arc.
Blade: 1-pinnate-pinnatifid, lanceolate, base narrowed, bulblet near the tip, glossy, hair-like scales, sparse above, dense below, broader scales on rachis and costa.
Pinnae: 18 to 28 pair, first pinnule pair larger, ear-like on lower pinnae, only the upper one larger higher up; pinnules adnate to the costa; margins serrulate-spiny; veins free, forked.
Sori: abortive, indusium: .

Culture Habitat: moist forests. Distribution: Yukon, southeastern Alaska to Oregon, western Montana. Hardy to -25°C, USDA Zone 5, cool climate required.

Distinctive Characteristics buds at the tips of fronds

Synonyms
Polystichum braunii (Spenner) Fée subsp. andersonii (M. Hopkins) Calder & Roy L. Taylor
Polystichum braunii var. andersonii (M. Hopkins) Hultén
Polystichum jenningsi Hopkins