A tale of two cotton-grasses

The white heads of cotton-grass are beginning to decorate the moorland. There are two species in this habitat, Common Cotton-grass (Eriophorum angustifolium) with multiple heads and Hare's-tail Cotton-grass (Eriophorum vaginatum) with single heads. Curiously, the former was easier to photograph in the wind than the latter! There's a third, uncommon, species, Broad-leaved Cotton-grass (Eriophorum latifolium), which is only found on the limestone.
The heads were once used for candle wicks, stuffing pillows and dressing wounds, and they aren't grasses at all, but related to the sedges.
Malcolm

Common Cotton-grass

Hare's-tail Cotton-grass