Carex pachystachya, commonly known as Chamisso sedge, is a perennial herb native to a variety of habitats including moist meadows, open woodlands, and along streams in western North America, from Alaska to Saskatchewan and south to California. It typically forms dense clumps of erect, grass-like stems that can reach up to 4 feet in height. The inflorescences are characterized by dense or open clusters of several spikes, with pistillate flowers enveloped in reddish or brown bracts. The fruit of Chamisso sedge is notable for being encased in a sac called a perigynium, which is a distinguishing feature of sedges.

Chamisso sedge is valued for its adaptability to different moisture conditions and its ability to thrive in both dry and wet areas, making it a versatile plant for naturalistic plantings and restoration projects. It is often used for erosion control and as a ground cover in riparian restoration efforts. In cultivation, it prefers full sun to part shade and can tolerate a range of soil types, provided they have good drainage. While generally low-maintenance, it can spread vigorously and may require management to keep it within bounds.CC BY-SA 4.0