Rumex brownii aka Hooked Dock

Rumex brownii, or swamp dock, belongs to the Polygonaceae family. This perennial grows in New Guinea and eastern and southern Australia. Kew lists it as a plant of subtropical regions. Australian records place it beside creeks and in other damp sites. It also grows in mountain and subalpine areas, often on clay. Damp lawns and pastures can support it as a weed. It is not native to Britain or Ireland.

Plants reach about 2 feet [0.6 metres] tall. The leaves can reach about 1 foot [0.3 metres] long. Plants For A Future records flowering from September to November. Each flower has both male and female organs. Wind carries the pollen. The supplied species records give no further flower or fruit details. In Britain, seeds have arrived with wool shipped from Australia. Plants established this way may last for a few years.

Swamp dock grows in sun or partial shade. It accepts sandy soil, loam, and clay. For cultivation, it prefers deep, fertile soil with plenty of humus. The soil should hold moisture but still drain well. Mildly acid, neutral, and mildly alkaline soils suit it. Its listed garden settings include bog gardens, lawns, and planted beds. Its presence in damp pasture also shows its weedy side. Growers can sow seeds in a cold frame in spring. Move seedlings into separate pots once large enough to handle. Plant them outside in summer, or divide established plants in spring.

The leaves have a recorded use as a cooked vegetable. Remove the midrib before cooking them as a leaf-beet substitute. The roasted root also has a use as a coffee substitute. These food uses come with a clear caution about oxalic acid. Leaves should not form a large part of the diet. Excess oxalic acid can bind calcium and reduce its availability. Cooking lowers the oxalic acid content but does not remove this warning. People prone to kidney stones or gout should take particular care. The source also cautions people with arthritis, rheumatism, or excess stomach acid.

The root provides a yellow dye when used with alum. Plants For A Future lists no known medicinal uses. Its food and dye uses offer reasons to grow it. Its occurrence as a lawn weed deserves equal weight when choosing a site. The supplied records give no species-specific pest or disease details. They also provide no hardiness rating or mature spread.