It's not a grass but a herb.

In the UK it is found only on Gower and in particular at Graves End Wall. It's an alpine species, tho', apparently, the British specimens are quite distinct from the European populations and some have posited that that the plant in the UK is a relic from the Ice Age.

Yellow Whitlow Grass

There are whispers afoot to bolt Graves End Wall. Give that it is likely that this would lead to greater traffic, I don't think bolting is is going to happen.