My poorly plum tree

[Daphne1411]

I've put another thread on another forum. I've not done these internet forum things before so I'm a bit green...... Can anyone help me please? I'm desperate to find out what the lumps on my plum tree leaves are. I've seached loads of pages, wikipedia, etc but I cannot find the same description of ailment that my plum tree has.

[Migueli]

A picture would help enormously. See if you can get a good close up.