Common Reed (Phragmites australis)
It has the vernacular name of Common Reed because it is SO common. You find Phragmites just about anywhere in lowland Britain where there is water! It occurs in fens, swamps, ditches, lakes and on riversides, both in brackish and alkaline waters, even in acid bogs!
This plant can cover large areas and forms an invaluable habitat for birds. Here in Dorset, of course, some parts of Poole and Christchurch Harbours and Radipole Lake and Lodmore are all examples of Phragmites reed beds. If you want to find Bearded Tit or Cettis Warbler, Water Rail or Bittern, even Marsh Harrier, then it is a large Phragites bed you need. They are also used by swallows and starlings for roosting, often in large numbers.