1.
young sansho leaves used as a garnish
In cooking, the young leaves of the 山椒 (Japanese pepper) tree, used as a fragrant garnish on soups, grilled fish, and spring dishes. Also refers more generally to the fresh buds or sprouts of any tree.
木の芽 (literally "tree bud") most often refers in cooking specifically to young 山椒 leaves, prized for their sharp, citrusy fragrance and used as a spring garnish on 吸い物 (clear soup), grilled fish, and bamboo shoot dishes.
Usage
A sprig is traditionally clapped once between the palms just before serving to release its aroma. Outside cooking, the word means the fresh buds of any tree; in this sense it is often read このめ, as in 木の芽時 (early spring, when trees bud).