Oenanthe pimpinelloides Corky-fruited Water-dropwort R DD N
This umbellifer has a strange distribution being extremely common in the London area, the south of England around Dorset and Hampshire but disappearing completely apart from the very occasional site here and there in the rest of the British Isles. It is virtually absent from Scotland, most of Wales and there is very little indeed in Ireland. This is now rated as a rare plant in Edition 3 of New flora of the British Isles by Clive Stace.