Sword fern (Polystichum munitum) is a large evergreen fern native to the moist forests of western North America. It is one of the most recognizable understory plants of Pacific coastal forests, often forming dense colonies beneath towering conifers such as Douglas fir, western red cedar, and hemlock.

The plant grows from a central rhizome that produces long arching fronds arranged in a circular clump. Each frond is composed of many small pointed leaflets that resemble the shape of tiny swords, giving the plant its common name. Mature fronds may reach several feet in length and remain green throughout the year, providing important winter structure in forest landscapes.

Sword fern thrives in shaded environments with rich organic soil and consistent moisture. In natural forests it often grows among mosses, fallen logs, and deep leaf litter, where it helps stabilize soil and maintain forest floor humidity.

Because of its elegant form and tolerance of shade, sword fern is widely used in woodland gardens and naturalized landscapes. Its evergreen foliage provides year-round texture while also supporting ecological health in forest ecosystems.