Carex

There does not seem to be a great deal of carex pendula on the Isle of Wight, even in the woods, so perhaps the soil or the climate is not quite right.

According to wikipedia, they like damp, heavy clay soils - while here on the island there is going to be a lot of chalk and gravel - unlike our own garden back on the mainland which ticks the heavy clay - if not the damp - part of the wikipedia specification. While Battersea Park probably ticks all three parts, certainly down by the lake. See reference 1.

But this morning, I did find this rather fine specimen, just down the lane from where we are staying. Perhaps they water it a lot.

Reference 1: http://psmv2.blogspot.co.uk/2016/01/carex-pendula.html.