Synonymy

Pure Sedge Godwin & Tansley 1929; Cladietum Tansley 1939; Cladium mariscus reed-swamp Conway 1942; Cladium mariscus primary fen Lambert 1951; Cladium mariscus stands Holdgate 1955b; Cladium mariscus society Poore & Walker 1959; Tall Cladium mariscus Haslam 1965; Cladium mariscus swamp Ratcliffe & Hattey 1982.

Constant species

Cladium mariscus.

Rare species

Utricularia intermedia.

Physiognomy

The Cladietum marisci comprises vegetation overwhelmingly dominated by Cladium mariscus. The gregarious stout shoots up to 2 metres tall form a sometimes open patchwork of clumps or a dense cover, often made virtually impenetrable by the tough leaves which are up to 3 m long and characteristically bent over, 1 m or more from the ground. This growth habit, the evergreen nature of the aerial parts and the thick accumulation of slow-rotting litter, sometimes more than 50 cm deep (Godwin & Tansley 1929, Conway 1942), can exclude all possible competitors. No other species is frequent throughout and pure stands are common.

Sub-communities

Cladium mariscus sub-community: Scirpo-Phragmitetum cladietosum Messikommer 1928; Caricetum elatae cladietosum Libbert 1932; Cladietum marisci typicum Krausch 1964 p.p.-, Cladietum marisci phragmitetosum Westhoff & Segal 1969; Cladietum marisci typicum, Cladium-Carex elata community, Cladium-Thelypteris community, Cladium sociation Wheeler 1980«. Here are included the most dense and/or speciespoor stands, ranging from pure Cladium, through open vegetation with occasional shoots of Phragmites australis or Juncus suhnodulosus and sprawls of Solanum dulcamara to mosaics of C. mariscus with sometimes abundant P. australis or scattered tussocks of Carex elata.

Menyanthes trifoliata sub-community: Cladium mariscus-Myrica gale sociation Spence 1964; Cladium mariscus-Utricularia intermedia nodum Ivimey-Cook & Proctor 1966; Cladietum marisci scorpidietosum Segal & Westhoff 1969; Cladietum marisci utricularietosum and caricetosum lasiocarpae Wheeler 1980«; Cladium mariscus-Rubus fruticosus-Myrica gale community Ratcliffe & Hattey 1982. In this sub-community, the cover of Cladium is more open and the plants often shorter, up to about 1 m tall. P. australis, J. subnodulus and C. elata are more frequent here and there are sometimes scattered clumps of Myrica gale but the really distinctive feature is the vegetation of the pools of standing water between the Cladium shoots.