Check this site "Sand-Mohn (Papaver argemone), Illustration", it will enlarge if you click on it.
The flower heads droop before opening, as described on the botany.cz link above, and it mentions they are red or purple/red with often black blotches at the base . Some of the leaves on the illustratioin do match this plant.
http://www.gbif.org/species/28...
