Riddle: What is that which has many leaves, but no stem?
When we heard that something has leaves, we think that it needs to have stem too; however, in this riddle this is not the case so, we can understand that this thing is not a plant.
A stem is the stick-like central part of a plant that grows above the ground and from which leaves and flowers grow, or a smaller thin part that grows from the central part and supports the leaves and flowers. Books have leaves or pages but since they are not a flower or any kind of a plant, they do not have stem.
The answer of this easy riddle is a book.