Juncus ensifolius, commonly known as Sword-Leaved Rush, is an evergreen perennial grass native to wetlands, including marshes, swamps, and the edges of ponds and streams in Western North America. It forms dense clumps of stems ranging from 20 to 60 centimeters tall, with flat, curving leaves that are mostly basal and vary in length. The inflorescence consists of multiple rounded clusters, each with numerous flowers. Flowers have dark brown to black tepals and typically three small stamens. The fruit is an oblong capsule with a beak at the tip. Sword-Leaved Rush is valued for its vertical form and textural contrast in water gardens and naturalized areas.

This plant is often used in rain gardens, bioswales, and as an accent in water features due to its affinity for wet conditions and its ability to filter pollutants. It thrives in full sun to part shade and prefers consistently moist to wet soils with slow to medium drainage. While it is generally low-maintenance, it can spread aggressively in ideal conditions, so care should be taken to manage its growth in smaller garden settings.CC BY-SA 4.0