Carex tenuiculmis, commonly known as Rootbeer Grass, is an evergreen perennial grass native to wetlands, bogs, and the understory of mixed forests in the Chatham Islands and Southern New Zealand. It typically grows to a height and width of approximately 1 foot (0.3 meters), forming dense clumps of fine-textured, arching foliage. The leaves emit a scent reminiscent of root beer when crushed, hence the common name. This sedge does not produce showy flowers, but its foliage provides year-round interest in the garden.

Rootbeer Grass is valued for its textural contrast and evergreen nature in garden settings. It is suitable for use in rain gardens, as a ground cover, or in borders where consistent moisture is available. It thrives in full sun to part shade and prefers moist to wet soils with good drainage. While it is adaptable to various soil types, it does not tolerate drought well. Carex tenuiculmis is relatively low maintenance, but it may require division every few years to rejuvenate and prevent overcrowding.CC BY-SA 4.0