Dulichium arundinaceum, commonly known as three-way sedge, is a perennial wetland herb belonging to the sedge family, Cyperaceae. This species is a distinctive member of its genus, characterized by its unique growth habit and ecological niche. It plays a role in wetland ecosystems, contributing to plant diversity and providing habitat for various organisms. Physically, Dulichium arundinaceum exhibits an erect, somewhat sprawling growth form. It typically reaches heights of 30 to 100 centimeters, though it can occasionally grow taller. The stems are triangular in cross-section, a common characteristic of sedges, and are smooth. The leaves are arranged alternately along the stem and are linear, tapering to a point, measuring about 5 to 15 millimeters in width. A notable feature of the leaves is their arrangement, which appears to be in three ranks, giving rise to the common name "three-way sedge." The inflorescence is a terminal spike, often appearing somewhat loose, bearing several spikelets. Each spikelet contains numerous small flowers, which are typically wind-pollinated. The fruits are small, hard, and dry, known as achenes, which are essential for the plant's reproduction and dispersal. The native distribution of Dulichium arundinaceum is widespread across temperate North America, extending into parts of eastern Asia. It thrives in wet environments, commonly found in marshes, swamps, ditches, along the edges of ponds and lakes, and in other saturated soils. Its habitat preference makes it an indicator of wetland conditions. While it is not widely cultivated as an ornamental, its naturalistic appeal and wetland habitat suitability make it a valuable component of ecological restoration projects and naturalistic water gardens where appropriate conditions can be maintained. It prefers full sun to partial shade and consistently moist to wet soil. Ecologically, three-way sedge is significant for its role in wetland plant communities. It contributes to the structural complexity of these habitats and provides a food source and shelter for various invertebrates and small vertebrates. Its ability to colonize saturated soils helps stabilize shorelines and prevent erosion. While not a primary food crop, its seeds and foliage may be consumed by some waterfowl and other wetland wildlife. There are no widely established ornamental, agricultural, medicinal, or culinary uses documented for Dulichium arundinaceum. An interesting characteristic of Dulichium arundinaceum is its adaptation to waterlogged conditions, facilitated by its rhizomatous root system which helps it spread and anchor in soft substrates. The triangular stems and the three-ranked leaf arrangement are key diagnostic features that distinguish it from other wetland plants, including true grasses and other sedges. Its presence is often indicative of healthy, functioning wetland ecosystems.