This fluffy headed wild flower is the Hemp Agrimony (Eupatorium cannabinum). This plant is native to most of Eurasia and it is a generous food source for pollinators in August. The plant has been used in traditional herbal medicine as an anti inflammatory.
In addition, there’s a curious story about the origin of the Latin name... the genus name pays homage to the ancient king Mithridates VI of Pontus, otherwise known as Eupator Dionysius (132BC - 63BC). King Eupator Dionysius was a poison collector and expert in herbal medicine who was paranoid about being poisoned. To make himself immune to poisons, the king “micro-dosed” with a variety of different poisons daily. When his kingdom fell to the Romans, the king tried to take his own life with poison - which unfortunately didn’t work! The story says that the king asked his loyal guard to finish the deed.
This story is an ironic example of “seemed like a good idea at the time”.