Eleocharis palustris subsp. waltersii, commonly known as Common Spike-rush, is a perennial herb belonging to the sedge family. It is native to marshes, fens, wet meadows, and the edges of ponds and streams across a wide range of temperate and tropical regions worldwide. This plant typically grows to a height of 20-50 cm and forms dense clumps of cylindrical, green stems. The inflorescences are small, brownish spikelets that appear from late spring to late summer, and while not showy, they are an important food source for waterfowl and other wildlife.

Common Spike-rush is valued for its ability to stabilize soil and filter water, making it a useful plant for wetland restoration and the creation of natural water filtration systems. It is also used ornamentally in water gardens and bog plantings. This sedge thrives in full sun to part shade and requires consistently moist to wet soil conditions. It is not particular about soil type, as long as the area is wet. While generally low-maintenance, it can become invasive in some conditions, spreading rapidly by rhizomes and potentially outcompeting other plants in the habitat.CC BY-SA 4.0