Grotty Fungus.

I have seen this many many times before on trees but have never asked the question What is it?
What causes it?
Is It detremental?
Is it curable?

 

Evening, dearest.

Looks like a canker, which is a diseased infection, and it is usually cracked and sunken. It will kill the branch if it circles it. There are different fungi and bacteria involved, depending on the tree. Some are specific to cetain trees. You should cut out canker back to clean wood and paint it with something like Abrex. It's not life threatening I don't think ... but I'm probably completely wrong here.

 

Not canker.

Its lichen, simply a type of algae that grows on the bark, no detremental efect on the tree whatsoever. If anything lichen shows clean air as it doesnt grow in poluted areas.

 

Yes agree with Pro Gard.

 

Me too. You see it a lot over here, especially on the weather side of trees.

 

Thanks guys........I just found this.

http://www.rhs.org.uk/advice/profiles1201/lichen.asp