Question
QUESTION: I have a deciduous tree (don't know the name - it flowers, then has green leaves in the early spring which turn deep red in late spring) in my yard in eastern Pennsylvania.  It now has a large number of irregularly-shaped attachments on the branches which are hard (like nut shells) and look like pods -but I've broken some of these open and there is nothing inside them.  What are these?  What should I do about them?  
Thank you.

ANSWER: Donna:

These may be some type of insect. Can you take and send a closeup photo? This will help with an ID.  Can you also give me an idea of the shape and size of these "pods"?  Does the tree seemed to appear affected by the presence of these objects?

Regards
Steve

---------- FOLLOW-UP ----------


tree pic 1   QUESTION: attached is a photo of the tree.


The 'pods' don't seem to affect the tree in any way.

Answer
Donna:
Thanks for the photo.  This looks like a disease called "Black Knot".  Here in Arkansas, we see it on plums.  Use "Google" Images to see some other photos.  These swellings are usually black and hard.  They can eventually kill the tree.  Pruning these structures is an option if there are not too many of them.  These galls look like an insect structure, but they are caused by a fungus called Dibotryon.  This is a contagious disease that affects only the plums (fruit and ornamental types)primarily. If they are all over the tree, the tree may need to be removed and destroyed, especially if you have other trees of the same type nearby.  You can read about this disease on the internet.  It is quite common here.  Pruning should ideally be done during the winter when the tree is dormant.

Let me know if this is indeed Black Knot.

Regards
Steve