Leaves is a collective noun for any leaves.
The biggest leaves in the game, used primary for house roofs, but as other leaves they can also be used to create ropes. They can also burn for a short time.
Small leaves are found on bushes and can also burn. They are used in the Prehistoric Shop recipes.
Palm leaves are the same as Medium Leaves, except they have another color and they have another name. They are used for the same things as Medium Leaves.