Cottongrass is not a
grass at all but a sedge (identified by the triangular
stems) of the genus Eriophorum. There are a number of
different species found in the Northern Hemisphere in damp
acidic situations particularly peat bogs, I suspect this one is
Eriophorum scheuchzeri though I am not a botanist and
didn't have an identification guide with me.
Picture copyright Paul Ward 2009.
Pentax digital equipment.