What is wrong with the tree?

Hello!
The tree near my house has been growing strange red growths out of its leaves for a few years. It didn't do that before. Look at the attached photos. Do you know why the tree is doing this? If it is sick, what kind of illness does it have? Some nearby trees also have these growths. I don't know the species of this tree.

Looks similar to one of the trees we used to have, it had some sort of bacteria that caused burls on the trunk and knobbly bits on the leaves. They are benign tumours and shouldn't really affect the tree... hopefully.

They are benign tumours and shouldn't really affect the tree...

They make it look scary.
It must be infectious, because many of the trees of this species in my neigborhood have this disease. It doesn't seem to go away.

Get hold of your local state ag representitive. They could give you some suggestions and they also might want to see it if it might have any possibility of economic effect on agriculture.

Your tree doesn't look like a Maple, but these sure look similar.

LMGTFY - Let Me Google That For You :wink:

I did some googling on this - first off, what type of tree is this? It looks like a fruitless (?) mulberry to me. Anyhow, what I found was that it appears to be something called "nipple gall" (note for anyone searching on this: turn safe search on, or narrow your results with words like "tree" or "leaf" or "leaves", unless you want to see some interesting results).

It appears to be some kind of infestation, fungus, or other infection; I don't know how or what the seriousness of it is, but if it is jumping from tree to tree, you may have a real problem on your hand. Once again, seeking professional advice would be the best solution.

Hmm - based on the above link, the damage is likely done; but not usually a "health issue" for the tree; just unsightly damage. Next spring, you and your neighbors should seek an arborist or such to come and spray your trees to prevent it.

Better Living Through Chemistry ... a.k.a. Lethal Chemicals!