A Tree From the Inside Out: A Glossary of Terms Related to Tree Anatomy
Trees come in a wide variety of types and species, but all trees share the same basic anatomy structure.
Knowing the basics of your tree can help you gauge the health of your tree. It allows you to know what to look for and where to look; allowing you to keep a better eye out for the first signs of potential disease.
Crown – The crown is the part of a tree that is above ground. Often the first signs of disease show up as dead or dying branches on the top of the crown.
Heartwood – The heartwood is the center of the tree, and is the support pillar. While it is not alive, it will not decay as long as the outer layers are still intact. It is the strength of the tree, and can support up to twenty tons.
Sapwood – This is the waterline for the tree. It passes water up to the leaves. As the sapwood grows, the old sapwood dies and produces new heartwood.
Cambium Cell Layer – This is the growing part of the trunk. It continually produces new bark from food passed down from the inner bark, and leaves. Auxins, which are produced by leaf buds, stimulate the growth.
Inner Bark – Also known as phloem, inner bark only lives for short periods of time. Its main job is to pass food to the inside of the tree. It then dies, and becomes part of the outer bark.
Outer Bark – The outer bark is what you see. The outside layer of the tree is waterproof and strong. It provides insulation from extreme heat and cold, and helps to ward off insects. The bark is continually rebuilt or strengthened from the inside of the tree.
Leaves – Leaves are responsible for making food which feeds the tree They bring the necessary oxygen, and make the food needed to help the tree grow – the process that is known as photosynthesis. A leaf also contains the substances that give the leaf is color. Often the first sign of disease shows up as yellow or dried leaves.