NVC community SD3 (Matricaria maritima - Galium aparine strandline community) is one of two strandline community in the British National Vegetation Classification system.
It is a fairly localised community of northern Britain.
Two constant species, Cleavers (Galium aparine) and Sea Mayweed (Matricaria maritima), are found in this community.
Two rare species, Oysterplant (Mertensia maritima) and Ray's Knotgrass (Polygonum oxyspermum ssp.
This community is found in many localities in Scotland, principally on the west coast, and on the northwest coast of England.