Festuca rubra

Not a very convincing picture admittedly. It's quite difficult to get a nice photograph of a grass in the middle of Winter (when this is being written). The common name is red fescue grass and it often forms a dense sward at the top of the salt marsh. It's a very common grass of maritime environments being extremely salt tolerant. You often find it's the main grass on cliff tops for instance. Its other common name invented by generations of Dale Fort sixth form students is "normal grass". This is not a genuine name but it does indicate that you may not find it very distinctive if you are unfamiliar with grasses. It has rolled leaves (you can roll them between finger and thumb). Sometimes it looks reddish towards the tips of the leaves. It could be confused with Puccinellia maritima but it lives higher up the marsh, generally looks greener and fresher and has no ligule.