Achillea ptarmica Sneezewort CC DD N
This is a plant known to country folk for many centuries. It prefers wet or damp habitats and so you will often find it by streams or in bogs and fens.
One of the early botanists John Gerard who wrote a famous botanical text Herball in 1597, reckoned that smelling this plant made him sneeze but its main use was as a cure for toothache. Eating the peppery roots would cause an increase in salivation.
Achillea ptarmica is found in those parts of the British Isles where damp meadows can flourish so one of the few areas where it is uncommon is in the dry Brecklands of East Anglia. It is common in northern Ireland but surprisingly less common in the south.