Scientific name Ruppia maritima/cirrhosa lagoon community
Common name Beaked/Spiral Tasselweed lagoon community
Community code SW1A


SW1A: Ruppia maritima/cirrhosa – Potamogeton pectinatus lagoon community   SW1A map: Ruppia maritima/cirrhosa – Potamogeton pectinatus lagoon community

Download full pdf synopsis: SW1A



This is a typically a submerged community dominated by Ruppia maritima or Ruppia cirrhosa. There are no other constant or frequent vascular species and only a limited number of infrequent associates. These are comprised mainly of other aquatic species, particularly Potamogeton pectinatus, Zostera marina and Zannichellia palustris, or of emergent species, mainly Phragmites australis, Bolboschoenus maritimus and Schoenoplectus tabernaemontani. These swamp plants, however, offer only sparse cover. Charophytes (Chara species and Lamprothamnium papulosum) are occasionally found in this community.



This is predominantly a community of lagoons and coastal saline lakes. Ruppia-dominated vegetation has also been observed in salt pans and on coastal mudflats, but little data have yet been collected to describe this aspect of the community.



No sub-communities are currently described.


Similar communities

This is a very distinct community which should not cause too much confusion. There are some similarities with the FW2F Potamogeton pectinatus – Myriophyllum spicatum aquatic community, but in that assemblage Ruppia is infrequent and Potamogeton species tend to dominate. On mudflats (e.g. at Bull Island, Dublin) Ruppia expanses may merge into SM1A Salicornia agg. saltmarsh.


Conservation value

Most examples of this community occur in water bodies that qualify as EU HD Annex I priority habitat 1150 Lagoons*.



This community is typically unmanaged but is threatened by impacts which affect lagoons, including drainage for purposes of agricultural reclamation, natural siltation and eutrophication.