Sparganium erectum aka Branched Bur Reed

Sparganium erectum is a water-loving perennial in the Typhaceae family. Gardeners know it as branched bur reed or common bur reed. Kew gives its native range as Europe to the Caucasus. It is native to Britain and Ireland. It grows along muddy or peaty shores and in shallow water. Its habitats include ponds, ditches, and marshes without grazing.

This upright plant keeps some leaves through winter. Its narrow leaves have a keel and reach 5 feet [1.5 metres] long. Garden plants reach about 3.3–5 feet [1–1.5 metres] tall. Their usual spread is 8.2–13.1 feet [2.5–4 metres]. They reach full size within two to five years. These widths are not a firm limit on growth. The plant can keep spreading where space and conditions allow. Its strong growth can become a nuisance without control.

In summer, branched stems carry small greenish-white flowers. Male and female flowers form separate clusters on the plant. Prickly fruits follow the flowers, starting green and turning brown. They measure about 0.4 inches [0.01 metres] across. The upright leaves, branched stems, and fruits give the plant its form. It suits pond edges in wildlife gardens and informal planting. Plants For A Future also lists it for bog gardens. That source notes its value for attracting wildlife.

Grow it at a shallow pond edge in sun or partial shade. The RHS allows water depths to 1.5 feet [0.45 metres]. Plants For A Future records habitats with shallower water. It accepts clay, loam, or sand and needs wet conditions. Acid, neutral, and alkaline soils all suit it. The RHS rates its cold hardiness as H7. Plants For A Future gives USDA zones 4–8. The RHS reports few problems with pests or disease. Remove old leaves and stems in spring. Divide plants in spring, or sow seed when ripe. The RHS gives a seed-sowing temperature of 15°C.

Plants For A Future lists cooked roots and stem bases as edible. It describes the cooked root as slightly sweet. The same source reports no known hazards. This does not establish safety for every person or pet. It also records a past use for chills. That remedy combined an infusion of this plant with other leaves. The record describes traditional use, not proof that the remedy works.