Introduction
The aquatic communities of the NVC were described in Volume 4 of '' British Plant Communities'', first published in 1995, along with the swamps and tall-herb fens. In total, 24 aquatic communities have been identified. The aquatic communities fall into the following six groups: * four communities of the water surface and sub-surface, in which duckweeds and/or Frogbit are the constant species; these communities ( A1, A2, A3 and A4) are found in moderately-rich to eutrophic standing waters * eight free-floating or rooted and submerged, pondweed communities ( A5, A6, A11, A12, A13, A14, A15 and A21) * six communities in which rooted water-lilies and pondweeds with floating leaves are the constant species ( A7, A8, A9, A10, A19 and A20) * three communities in which water-crowfoots and/or starworts are the constant species ( A16, A17 and A18) * two hairgrass and quillwort communities ( A22 and A23) * a single community characterised by free-floating vegetation found in impoverished base-poor standing waters ( A24).List of aquatic communities
The following is a list of the communities that make up this category: * A1 ''Lemna gibba'' community ''Lemnetum gibbae'' Miyawaki & J. Tx. 1960 * A2 ''Lemna minor'' community ''Lemnetum minoris'' Soó 1947 * A3 ''Spirodela polyrhiza - Hydrocharis morsus-ranae'' community * A4 ''Hydrocharis morsus-ranae - Stratiotes aloides'' community * A5 ''Ceratophyllum demersum'' community ''Certaophylletum demersi'' Hild 1956 * A6 ''Ceratophyllum submersum'' community ''Certaophylletum submersi'' Den Hartog & Segal 1964 * A7 ''Nymphaea alba'' community ''Nymphaeetum albae'' Oberdorfer & Mitarb. 1967 * A8 ''Nuphar lutea'' community * A9 ''Potamogeton natans'' community * A10 ''Polygonum amphibium'' community * A11 ''Potamogeton pectinatus - Myriophyllum spicatum'' community * A12 ''Potamogeton pectinatus'' community * A13 ''Potamogeton perfoliatus - Myriophyllum alterniflorum'' community * A14 ''Myriophyllum alterniflorum'' community ''Myriophylletum alterniflori'' * A15 ''Elodea canadensis'' community * A16 ''Callitriche stagnalis'' community * A17 ''Ranunculus penicillatus'' ssp. ''pseudofluitans'' community * A18 ''Ranunculus fluitans'' community ''Ranunculetum fluitantis'' Allorge 1922 * A19 ''Ranunculus aquatilis'' community ''Ranunculetum aquatilis'' Géhu 1961 * A20 ''Ranunculus peltatus'' community ''Ranunculetum peltati'' Sauer 1947 * A21 ''Ranunculus baudotii'' community ''Ranunculetum baudotii'' Br.-Bl. 1952 * A22 ''Littorella uniflora - Lobelia dortmanna'' community * A23 ''Isoetes lacustris/setacea'' community * A24 ''Juncus bulbosus'' community. {{NVC