It means the head and refers to the head of a bonsai tree or the crown of a tree. In addition to atama, names of other human physical parts are used for bonsai, including kubi (neck), mune (chest), te (hands), and ashi (feet). The head is an important part of bonsai and whether one can bring the head together is said to be a way to gauge his or her skills. There may be times when an expression ”the head fits well” in bonsai is used to describe a well-shaped head. Generally, the more roundish the head, the better it is for expressing a sense of a large old trunk.

translated by Kyodo News