Mugwort

This is a common plant growing on rough ground; I guess it would qualify for classification as a ruderal species. According to Grigson it has an ancient association with magic and medicine, known across Europe as the Mater Herbarum or Mother of Herbs. I would be hung in houses to ward off evil.
Other local names include St John's plant, Old Uncle Henry, Sailor's tobacco and, according to Wikipedia, Naughty Man.
It's Latin binomial is Artemisia vulgaris and Wormwood, A. absinthium, is in the same genus.