Scientific name Potamogeton pectinatus – Myriophyllum spicatum aquatic community
Common name Fennel Pondweed – Spiked Water-milfoil aquatic community
Community code FW2F


FW2F map: Potamogeton pectinatus – Myriophyllum spicatum aquatic community

Download full pdf synopsis: FW2F



The fine leaves of Potamogeton pectinatus dominate this aquatic community and it is the only constant species. Occasionally, it is accompanied by Potamogeton berchtoldii or the whorled stems of Myriophyllum spicatum. More rarely, one may find some Ruppia maritima/cirrhosa (in more saline waters), the floating duckweeds Lemna trisulca and Lemna minor, or other pondweeds.



This community is to be found mostly in lagoons with lower salinity, but also occurs in lowland rivers and freshwater lakes. It is associated with fairly base-rich and distinctly eutrophic waters.



No sub-communities are currently described.


Similar communities

The dominance of Potamogeton pectinatus differentiates this community from the SW1A Ruppia maritima/cirrhosa lagoon community in which P. pectinatus may also occur.


Conservation value

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



This community is typically unmanaged. It is mainly threatened by impacts which affect lagoons, including drainage for purposes of agricultural reclamation and natural siltation. The association with nutrient-enriched waters mean that eutrophication of both lakes and rivers is likely to affect its abundance.