This erect perennial herb is mostly found near habitation in lightly shaded habitats, including waste ground, roadside-banks, hedgerows, scrub and woodland, but it also grows on riversides. It reproduces prolifically from seed and can be very invasive. Generally lowland, but reaching 380 m at Upper Glenlivet (Banffs.).
P. sempervirens, introduced to British gardens before 1700, is frequently grown in gardens. It was known from the wild by 1724. Already widespread at the time of the 1962 Atlas, it has increased further during the past forty years.
Native of S.W. Europe, but naturalised in W. Europe north of its native range.