Leaves

Leaves are a type of block. They are very abundant in normally generated servers, appearing on every tree. Leaves have one face which is put on all 6 sides of the block.

Leaves are available for use in Creative mode. They are often used in making plants, foliage, tree houses, and, in pre-Glass times, windows. In Survival mode, Indev, Infdev, and Alpha, leaves cannot be obtained. Busting leaves will instead sometimes drop Saplings which will allow the player to plant a new tree. In Survival, Indev, Infdev, and Alpha however, if the trunk of a tree is Destroyed, the leaves will automatically disappear over time, dropping saplings in the process. Leaves are very weak blocks, they will blow up in an explosion and are flammable.

Trivia

 * Leaves were used as windows before Glass was implemented.