Epipactis helleborine
This species of orchid is pollinated by several species of Hymenoptera, particularly the common wasp, but also other species in the genera "Vespula" and "Dolichovespula". Flowers release a sweet nectar to attract the wasps, which has an intoxicating effect on them. Eight varieties of "Epipactis helleborine" in central Europe (Lower Silesia, Poland) had their nectar studied and they were found to contain naturally occurring oxycodone (as well as another narcotic-like opioid) in minute amounts.