Common Reed - Phragmites australis

Phragmites australis or common reed is a colonial plant, spreading by perennial rhizomes (roots) which can reach over 10 m long, often forming large dense stands. Common reed grows vigorously in wetland habitats such as marshes, swamps, ditches, streams, lakes and ponds.

Description

Phragmites australis is a tall reed producing annual cane-like (round and hollow) stems up to 4 m in height. Leaf blades are flat up to 45 mm wide which taper to long slender points and are arranged alternately. The leaves are attached to the stem by a smooth sheath, bearing wing-like extensions at the leaf base, with a fringe of fine hairs next to the stem. Flowers are borne on a very large, many branched inflorescence up to 60 cm long and are usually purple. Up to 6 flowers at a time are arranged in spikelets. Small branches between the flowers bear long white silky hairs. Flowers are composed of a hairless ovary, bearing 2 scales, with 3 pollen bearing stamens, except in the lowest floret which has 1-3 stamens.

Phragmites australis transfers atmospheric oxygen to the rhizome and out through the roots ultimately to the gravel and rhizosphere. This feature permits roots to respire aerobically and to grow in soil conditions that are often anoxic.

Uses

Common reed has been harvested in the past for building houses and thatching roofs, for making boats, jewellery, pen tips and paper. Perhaps its most important use in is the creation music as part of the mouthpiece in most woodwind instruments.

Since the early 1970's common reed has been found to play an important role in water treatment processes. Since then research has shown that reedbeds are an effective, reliable, sustainable and economical water treatment method. Reedbeds are now planted to treat waste water onsite both on a domestic and commercial scale across the UK.

In suitable conditions common reed has been shown to be a potential producer of biomass. It is capable of producing up to 60 tonne per ha of dry matter annually for a number of years, though 20-25 tonne per ha is a more standard return This can be used for fibre or energy production.

Wildlife Benefits

Beds of Phragmites australis are among the most important habitats for birds in the UK. They support a distinctive breeding bird assemblage including six species of conservation concern the bittern (Botaurus stellaris), marsh harrier (Circus aeruginosus), common crane (Grus grus), Cetti's warbler (Cettia cetti), Savi's warbler (Locustella luscinioides) and bearded tit (Panurus biarmicus). Reedbeds also provide roosting and feeding sites for migratory species, including the aquatic warbler (Acrocephalus paludicola) and are used as roost sites for several raptor species in winter.

Five GB Red Data Book invertebrates are also closely associated with reedbeds including the red leopard moth (Phragmataecia castanaea) and rove beetle (Lathrobium rufipenne).

Many of the UK's largest reedbeds are notified as SSSI/ASSI and many are notified as Wetlands of International Importance under the Ramsar Convention and as SPAs under the EC Bird Directive.