Pummelo has religious importance for Chinese, especially during new year celebration, this is why chinese immigrants spread pummelo tree everywhere where they settled.
It is a simbol for abundance, prosperity, to have children, good health, family unity.
Also pummelo leafs are very important in chinese tradition, they are using them as a protection against bad ghosts. For example, they have leaf in pocket, when attend funeral, or put some leafs to the bath, when came back home. You can buy whole branches for this purpose on chinese market.