Perennial, that bends down and roots at the lower joints. When growing in the open the stems can reach 3 feet tall and when leaning through other vegetation, stems can be over 12 feet long. Stems are round in section. Joints are very hairy. Leaf blades are flat, smooth, 3/8 to 5/8 inch wide and 4 to 12 inches long. Leaf sheaths are hairy with pustule-based hairs. Seedheads with 8 to 20 branches that have an erect “signal flag” appearance. Flowers and seeds are on the lower side of the branches, and the seeds are wrinkled. Grows in moist to wet disturbed and cultivated areas, but is most common in ditches, and often moves into cultivated areas from infested ditch banks.