Scientific name Littorella uniflora – Ranunculus flammula aquatic community
Common name Shoreweed – Lesser Spearwort aquatic community
Community code FW1A


FW1A map: Littorella uniflora – Ranunculus flammula aquatic community

Download full pdf synopsis: FW1A



Littorella uniflora is the key character species of this aquatic community and the only constant. It is frequently accompanied by Juncus bulbosus and occasionally by Lobelia dortmanna, Baldellia ranunculoides and Eriocaulon aquaticum Ranunculus flammula is frequent, growing in shallower waters, whilst Myriophyllum alterniflorum can occur at greater depths. Juncus articulatus, Eleocharis multicaulis, Carex viridula, Agrostis stolonifera and Mentha aquatica occur occasionally at the terrestrial transition.



This community is typical of the nutrient-poor, clear shallow waters of oligotrophic lakes on acid stony substrates, but may occur in more mesotrophic lakes.



No sub-communities are currently described.


Similar communities

From the closely-related other communities in this group, FW1A differs chiefly by the abundance and frequency of Littorella dortmanna.


Conservation value

Many examples of this habitat will correspond with EU HD Annex I habitat 3110 Oligotrophic lakes. Eriocaulon aquaticum has a distinctly restricted distribution in Ireland.



This community is typically unmanaged. The main threats to the lakes in which it occurs are eutrophication from agriculture and forestry, and inflow of suspended organic sediment from degraded peatlands.