The deep green leaves of sword fern (Polystichum munitum) are leathery yet graceful–and they are indeed shaped like swords. The lance-shaped leaves are made of smaller leaflets also shaped like a pointed blade. At the base of each of these pinnae, a thumb (or, hilt?) shaped lobe points toward the tip of the leaf.
Sword fern is a ubiquitous denizen of the woods from Alaska to California. It can grow singly or in dense stands; in forest, brush, or on open hillsides. Historically it had many uses among the western tribes–from food to mattresses to poultices to good luck charms for fishing and childbirth. They were used to line cooking pits, as placemats, and as flooring.
Flowers Of Marin 