This is the flower of the horned poppy (Glaucium flavum), another from Barry’s garden.
It’s a stunning flower, but what I really like about this plant are the blue/green leaves. They have a very interesting shape and structure, and are covered with tiny hairs. They’re the kind of leaves Karl Blossfeldt would have photographed. I checked my book shelf and they’re not in there, but that’s not to say he didn’t, just that they aren’t in the book I have.