Rumex britannica, commonly known as Greater Water Dock, is a perennial herb that may be deciduous or semi-deciduous depending on the climate. It is native to wetland habitats such as marshes, fens, and the edges of ponds and rivers in the Eastern and Central United States, as well as parts of Canada. This plant typically grows to a height of 3-6 feet (0.9-1.8 meters) and a width of 2-3 feet (0.6-0.9 meters). It has a robust, upright form with large, lance-shaped leaves and produces inflorescences of green and pink flowers in the summer, which are not particularly showy but are interesting for their architectural structure.

Greater Water Dock is valued for its ability to thrive in wet conditions and is often used in water gardens, rain gardens, and naturalized wetland plantings. It is also beneficial for wildlife, providing habitat and food for various insects and birds. In cultivation, it requires consistent moisture and can tolerate standing water, making it suitable for areas that are too wet for many other plants. It prefers part shade but can tolerate full sun in cooler climates. While not commonly afflicted by diseases, it can become quite large and may require management to prevent it from dominating smaller plants in the garden.CC BY-SA 4.0