Rashi on Numbers 6:4/רש"י על במדבר ו׳:ד׳

1חרצנים are THE KERNELS....

2זג are THE HUSKS (skins) outside. They are called זג (a term also used for a bell) because the kernels are inside them as the clapper is in the bell (cf. Siphre; Nazir 34b; 39a).