The earlier flowering grasses are going over now and the later bents and other species starting to send up flowering spikes. Yorkshire fog is very easily identified with its silvery spikes that often do not seem to open fully and it grows in several places in The Green Sanctuary. In the picture below one of the only open spikes is on the far right.
Apparently, the plant is called 'Yorkshire fog' because it was widely grown in Yorkshire in the 18th century to be threshed for its seed. So far as I can discover the seed was used for sowing to produce a quick growing 'ley' of palatable young grass for farm animals.