bark
The outermost part of a tree is the bark. Beneath this is the cambium. Beneath this is the late wood. Then the early wood. Late and early wood are both sapwood. The heart wood is the darker wood in the middle of a cross section. Finally, the soft center is the pith.
If you mean the rough brown part that protects it, it is the bark.
bark
Bark
the outer part of a tree trunk
the outer part of a tree trunk
the outer part of a tree trunk
The outer skin of an oak tree is called the bark. It is also known as rhytidome.
The outer skin of an oak tree is called the bark. It is also known as rhytidome.
the outer part of a tree trunk
The outer layer of a tree is called the bark.
It is normally called the tree's bark.
bark.
Bark
the Auricle
the center part of the tree is called the core.