Not all trees in a magical forest are made of wood bark.
Dragon Trees are aptly named for their bark which resembles a dragon's scales. These trees are actual cocoons which a special type of dragon species morphs into as they hibernate. The Dragon Trees are included with the Wargamer Tree Set.
The power of a dragon tree lies within the consumption of the tree bark. If a character is able to harvest a few scales and then brew them in as little as an ounce of liquid...the character will gain the power of flight for a brief amount of time.
Dragon tree bark is a highly sought after ingredient for any character that regularly uses magic. It's a great idea to already have a bit brewed in case a quick retreat is necessary, or you happen to be confronted with an impassable object.