Member of the Polygonaceae family.  Swamp smartweed reaches a height of up to 3 feet, and it grows in marshes or ditches over much of the United States.  Its leaves are alternately arranged along its stem, and are linear-lanceolate in shape.  Leaf petioles are wrapped in an ocrea where they meet the stem.  Small, greenish/white flowers grow on erect racemes atop the plant.  Swamp smartweed can sometime bear pinkish flowers, and it is considered a semiaquatic plant.  Blooms July-October.