Daucus carota Wild Carrot CC DD N
On the dunes, cliff tops and in any of the grassy areas near the seaside you can often find this umbellifer. In most cases when it has finished flowering, the seeds of the umbel make a concave shape as does the flower sometimes. This photo shows unusually convex versions growing with blue Jasione montana (Sheepsbit Scabious). This could be ssp gummifer (Sea Carrot) which according to R H Roberts in his flora Flowering Plants and Ferns of Anglesey does grow near South Stack.
Although most commonly associated with coastal sites, this plant is recorded from all over England, most of Wales and Ireland. Only in the central highlands and north of Scotland does it retreat to the coast.