It's a poppy. I don't know which species. The photograph is from World War I.
The poppies were made famous by a poem, "In Flanders' Fields," which begins:
In Flanders' fields the poppies grow
Between the crosses, row on row.

It is about a military cemetery, something to do with honoring the war dead by
making the world a better place, otherwise:
We shall not sleep, though poppies grow
In Flanders' fields.

It is the equivalent of Israel's kalaniot (poppy anemones).
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)