Buds are exciting things to watch. They develop very quickly in spring, swelling and getting longer more or less visibly day by day.

The outside of the bud is covered in tiny scale-like leaves. They protect the tiny shoot inside from harsh weather. All flowering plants have buds, but each kind of deciduous tree has distinctive buds which can be used to identify it. For example the beech has long, brown, cigar-shaped buds while the ash has more rounded black buds.

When the shoot is ready to grow, the protecting scales fall away. Large amounts of water pump into the shoot to make it expand and unfurl its leaves so it can start to make food quickly. Some shoots also have flowers which may grow quickly when the bud bursts open.

What is going on inside is that the petals are forming. In this picture you can see the outer scales of the bud are just being pushed aside by the leaves.