What type of fungus is this?

[TonyG]

There's some sort of black tarlike gunk growing on my neighbors fruit tree. It is all over the branches in black clumps, how can I identify this?

Thanks,
Tony

 

[Elmore]

Black knot

Sounds like black knot fungus. See the sites below for info.

http://ohioline.osu.edu/hyg-fact/3000/3011.html

http://www.gov.on.ca/OMAFRA/english/crops/facts/91-046.htm