Rev. Modius with four corn ears and poppy, ANNONA AVG.
A modius was used to measure grain (corn, wheat, barley, etc.) or various other dry or solid commodities. It resembles an inverted bucket resting on three legs and usually contained a third part of an amphora. The reverse type signified the emperor's benevolent distribution of grain among his subjects.
Obv. Antoninus Pius laureate right.