Dull with a cold wind.
It was difficult to walk through this area without breathing in clouds of midges.
My first real puzzle in mosses. This keys out closest to Rhytidiadelphus triquetrus, but this is given as 'especially on calcareous clay soils'. This is on acid heath. ID confirmed.
The two nerves (below) reach more than half-way along the length of the leaf, and the margin is very slightly toothed.
