An annual occurring as a casual garden escape on roadsides, waste ground and rubbish tips, and occasionally in arable fields as a relic of cultivation for poppy seed. Lowland, with one record at 410 m (Eisteddfa Gurig, Cards.).
This species is a medicinal, culinary and ornamental plant. Its seeds have been found in Bronze Age archaeological deposits and are frequently found from the Iron Age onwards. It is widely cultivated as a garden plant. Subsp. somniferum is the common taxon, whilst subsp. setigerum is a rare casual which might be a distinct species (Stace, 1997).
Probably native of the eastern Mediterranean region, but native distribution obscured by its spread in cultivation.