Why are my leaves solid and hollow in my world?

According to the information I know, the leaves in my world are divided into solid leaves and hollow leaves. Solid leaves are the ones that usually grow on tree trunks, while hollow leaves appear in some specific biota, such as coniferous forests. Hollow leaves generally appear at a certain distance from the trunk and are hollow.

However, I don't know what kind of leaves you mean. If you mean solid leaves, then they are not hollow. If you mean hollow leaves, they are hollow themselves.

If you have any other information about this problem or need further explanation, please provide it and I will try my best to help you.