I paid a very brief visit to the coast today, and saw some species that I only find there.
The 6-spot Burnet Moth can be very numerous in grassy areas at the coast. I've seen fields full of them.
Wild Carrot - Daucus carotta - is also a coastal plant, although I do know of one inland riverbank (on limestone) that has some.
Lady's Bedstraw is usually found at the margin between grassy areas and dunes.
Then it rained. Again.