Other - Somniferum vs. Rhoeas

[Madcow]

SWIM recently noticed that a neighbor of his has been growing poppies. SWIM doesn't know what kind they are, but speculates they are either P. Somniferum or P. Rhoeas.

SWIM scored one of the pods and a latex came out. It was a pungent, bitter, alkaloid-type scent. SWIM has never smelled or tasted opium before and has no idea what it's supposed to taste or smell like. Is there any way to easily identify what species it is with the given knowledge of color of flowers when they were blooming, smell of latex, shape of the bulbs, etc..?