Biology

This plant is a perennial, and the flowers appear in July and August. It does not like disturbance, and cannot survive regular cutting or ditch clearance, but can tolerate the occasional slubbing of its ditches and moderate grazing. However, whilst cattle and other stock seem to be immune from the effects of the plant's poison, dairy cows are discouraged from browsing it as it imparts an unpleasant taste to their milk.