Leaves is also a game feature of Minecraft. More information can be found on the Minecraft Wiki at Leaves.
There are 6 types of Leaves, one for each type of tree in Minecraft. They can be obtained by using Shears or a tool with the Silk TouchEnchantment on the leaves, or by unlocking a Trade that will let you convert Saplings to leaves.
In The Park you can get Birch Leaves, Spruce Leaves, Oak Leaves and Jungle Leaves.
To get the Dark Oak Leaves or the Acacia Leaves you will need their respective Minion, the Dark Oak Minion or the Acacia Minion. You can also obtain Dark Oak Leaves from placing and harvesting them from a Roofed Forest Island too.