This, like other docks, is a member of the Polygonaceae family, which also contains buckwheat and smartweeds. The family name means "many joints", which refers to the appearance of the stems.

Swamp dock grows up from the standing water of our wetlands, and is generally found in swamps and wet woods. It is up to 3 feet tall with large, erect, lanceolate leaves on red stems. The yellow-green drooping flowers appear in late April to early May on long stalks. These flowers have 6 sepals, but no petals. The fruits, which are eaten by waterfowl, are about half the length of the stalk on which they hang.