Water Foxtail (Alopecurus geniculatus), also known as Marsh Foxtail or Creeping Foxtail, is a low-growing, cool-season pastoral grass native to Europe, Asia, and North Africa, and now found across temperate regions worldwide. A member of the Poaceae family, it is typically found in wet meadows, marshes, ditches, floodplains, and along the edges of ponds and streams, thriving in saturated or periodically flooded soils.

This species is distinguished by its creeping growth habit, geniculate (bent or knee-like) stems, and soft, foxtail-like flower spikes that appear in spring and early summer. Its spreading rhizomes and stolons allow it to form dense mats, making it effective for ground coverage in wetland pastures.

Water Foxtail is valued as a forage grass for grazing animals, especially in seasonally wet environments. It contributes to soil stabilization and wetland biodiversity, offering habitat and food for wildlife. Its tolerance of fluctuating water levels makes it ideal for flood-prone landscapes.