Rumex conglomeratus aka Green Dock

Rumex conglomeratus belongs to the dock family, Polygonaceae. It is a perennial: it lives for more than one year. Its common names include clustered dock and sharp dock. Its native range spans Macaronesia and north and south Africa. It also spans Europe, central Asia and the western Himalaya. The RHS lists it as native to Britain and Ireland. It grows in regions with a temperate climate.

This dock grows about 3.3 feet (1 metre) tall. It grows in damp grassland and sometimes in woods. Plants For A Future notes confusion with Rumex sanguineus. Check the name when choosing plants or using plant guides. It flowers from July to August. Each flower has both male and female organs. Wind moves pollen from flower to flower. The supplied species evidence gives no more flower or fruit details.

Grow it in sun or part shade with moist soil. It accepts sand, loam and clay soils. It tolerates slightly acid, neutral and slightly alkaline soil too. For best growth, use deep, rich soil with much humus. The soil should hold moisture but still drain well. Plants For A Future says frost does not harm it. The evidence gives no exact hardiness zone. Suggested sites include meadows and woodland gardens with patchy shade. Shaded edges are another suggested site. Sow seed where it will grow in spring. Divide plants in spring too.

Records note the use of leaves as cooked greens. Their bitter taste grows stronger as they age. You can eat the seeds raw or cooked. Mix ground seed with flour for bread or biscuits. The small seeds take work to gather. Plants For A Future rates its food value one out of five. Leaves can hold high levels of oxalic acid. Cooking lowers the amount, but large servings remain unsuitable. Oxalic acid can limit the calcium the body can use. People with kidney stones, gout or arthritis should take care. The source also warns those with rheumatism or hyperacidity.

Folk records describe root treatments for scurvy and bleeding. They also note root ointments and leaf treatments for skin problems. These records show use, not proof that treatments work. People gathered roots in early spring and dried them for storage. Plants For A Future rates its medicinal value two out of five.