Papaver somniferum
At least 17 finds of "Papaver somniferum" from Neolithic settlements have been reported throughout Switzerland, Germany, and Spain, including the placement of large numbers of poppy seed capsules at a burial site (the "Cueva de los Murciélagos", or "Bat Cave", in Spain), which has been carbon-14 dated to 4200 BC. Numerous finds of "P. somniferum" or "P. setigerum" from Bronze Age and Iron Age settlements have also been reported.