Sparganium erectum (05/05/2012, Kew Gardens, London)
Position: Full sun to partial shade
Flowering period: Summer to early autumn
Soil: Wet (10cm -30cm below water level)
Eventual Height: 1.2m
Eventual Spread: 0.6m
Hardiness: 5a – 9b
Family: Sparganiaceae
Sparganium erectum is an emergent, deciduous, perennial plant which grows in still or slowly flowing water. Its mid green leaves are strap like and arching, with distinct brown tips up to 1.5m long and 15mm and are triangular in cross section. Its white monoecious flowers are compacted racemes, borne on branched flowering stems. The male flower heads appear above the female heads in the same branched stem. Its fruiting heads are comprised of achenes and are up to 3cm across and ripen in autumn. Its roots are rhizomes which enables this plant to spread, this is its main route to propagation.
Sparganium erectum, commonly known as Bur-reed, Exotic Bur-reed or Branched Bur-reed, is native to most northern temperate regions (including the UK). In its native habitat it is found at the margins of water bodies including ponds, lakes, rivers, streams, canals and drainage ditches. It is listed by the US federal government as a noxious weed and should not be planted in the USA.
The etymological root of the binomial name Sparganium is from the Greeksparganion, the name used by Dioscorides. Erectum is from the Latin meaning ‘erect’, referring to the habit of the plant.
The landscape architect may find Sparganium erectum useful as part of a native (UK) wetland planting scheme. This plant can also be used effectively as part of water purification system as it will tolerate eutrophic conditions. It will not grow in fast flowing water. It will not tolerate long periods of water deeper than 50cm.
Ecologically, S. erectum stands provide valuable habitat for nesting, roosting and feeding wildfowl. The fruits of this plant is an important source of food for wildfowl in late autumn and early winter. The larvae of some moths feed on this plant.
S. erectum prefers wet, deep silty soils. It prefers a water depth of between 10cm – 30cm It tolerates most pH of soil.
S. erectum requires little maintenance. Control of it spread may be carried out by manually uprooting unwanted stands, regular cutting between July and August, spraying with Glyphosate between July an September, or allowing livestock controlled access to the water body (they will eat it)
