There is some thing sinister about the name black sedge (Carex nigra)! The black sedge conjures up thoughts of a plant spreading out across the world devastating everything in its path in an uncontrollable and relentlessness expansion. A bit like the 'Day of the Triffids' I suppose! This is, of course just me and my mind ... or is it?
Also known as common sedge this is, indeed, probably one of our most common and familiar sedge species. It has blueish, vertical sword-like leaves and flower-heads, called catkins on sedges that are distinctively black when they emerge and the resulting seed heads are black too.
Black sedge spreads rampantly and where it occurs it will be in some abundance. It needs quite damp soil to survive and so its extent is limited by the ground conditions but it will often take over and fill the entire area of slack fresh water and boggy conditions around ponds, lakes and marshes.Carex nigra: the black sedge