Conopodium majus Pignut CC DD N
This is a very common plant on our acid Cheshire sandstone and an umbellifer that is fairly easy to identify. It is actually quite a small plant usually reaching 0.5 m maximum and always seems to start with drooping flower heads when in bud. The feathery leaves are also a give-away but finally you might try to eat the tubers raw or cooked which are supposed to taste of brazil nuts.
This plant is found throughout the British Isles and Ireland.