Western Sword Fern

Description:

Polystichum munitum (Western Sword Fern) is an evergreen fern native to western North America, where it is one of the most abundant ferns occurring along the Pacific coast from southeast Alaska south to southern California, and also inland east to southeastern British Columbia, northern Idaho and western Montana, with isolated populations in interior northern British Columbia, the Black Hills in South Dakota, and on Guadalupe Island off Baja California.

Notes:

This was one of the few things growing under the Redwoods at the foot of Mt Tam. They must like acidic soil.