disease
A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...
in
tree
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...
s that causes the bark of the plant to become hardened and tough, restricting the growth of the trunk. It is caused by a sudden restriction of the tree's growth, the rubbing of livestock against the trunk, or by
lichens
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.bark, cutting it along the grain of the tree, or by scraping away all of the diseased bark.
References
Bibliography
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* Crabb, George. ''The Book of Knowledge: Or, An Explanation of Words and Things Connected with All the Arts...'' Leavitt & Allen. 1858.
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{{plant-disease-stub
Tree diseases