untrue -- growing them in US is quite legal . cutting them for the sap (opium) is illegal and in my opinion a waste of time.
myself and others that i know have tried crop after crop grown from tasmanian, afgan, indian and other strains obtained from legit ethnobiological outfits.
all have germinated, grown to maturity and yielded considerable sap .
no one that i know has had any luck regarding potency . none, whether smoked, eaten or tinctured to home made laudanum .
papaver somniferum is the first thing to stick up through the snow in the spring.
it doesn't take a green thumb to grow the almost weed like flowering plant.
i and my fellow growers have hunches but no real idea of why to bountiful sap, which quickly oxidizes into brown dense matter that looks and tastes just like the real stuff i used to get in south east asia.