The tree outside my window has developed black spots on its leaves. What is it?

Question

I think the tree is a 10yr old maple and I've never seen such black spots before. Other trees don't seem to have it, but they're not maples.

The spots are about a quarter in size and they're all over the tree. Is it going to die? Or is it just a temporary disease, like a human chickenpox?

Answer 1

we have them too, it's a fungus and the disease is called "tar spot."
the appearance of the fungus is dependent on the weather, and the amt. of rain. one year the spots started to appear in july/august and all the leaves fell off. but the trees are still okay, this year the spots are appearing late but still look sickly. difficult to say when this disease is going to be eradicated, it's been around for 5-6 years now

Answer 2

Building on what Mathew said the Tar fungus growth does depend on the weather. At any point in the life of this tree it may have had many encounters with spores from this fungus but the limited number that did germinate with the given rain were easily dealt with by the plant. There was probably some very heavy rain prior to this fungus outbreak that allowed for more of the fungi to germinate and penetrate the outer surface of the leaves.

As long as the tree still has leaves able to photosynthesize the plant should not die. Always remember disease in plants is not the norm when it encounters pathogens, it is the exception.

As for the 'temporary' aspect of your question, plants generally acquire resistance to many fungal pathogens after their first exposure using signal messengers that are diffused throughout the plant in a process called Systemic Acquired Resistance. If the whole plant is covered it is likely that something is interfering with the SAR pathway. It would help your search for knowledge if you found out what other trees you see this fungus on that are nearby because it is possible that the fungus affecting your maple is a variety usually associated with one of these other species and if some mutation was acquired by the fungus while on the other species it may be better able to evade the defenses of the maple than the tar spot variety the maple is used to.

Answer 3

Typically a "disease" that is most commonly associated with Tangs and Surgeonfishes, but one that can be contracted by other species as well, what is referred to as Black Spot Disease, Tang Disease or Black Ich is actually caused by an infestation of tiny Genus Paravortex member turbellarian flatworms.

Although parasitic organisms that are much less dangerous and life-threatening, as well as rather easy to get rid of compared to other ich diseases such as Oodinium, Cryptocaryon, and Brooklynella, nonetheless it is a problem that needs to be treated upon recognition to eradicate infected fishes of these parasites.

The Life Cycle of These Worms

Living in the substrate until mature, an adult worm seeks out a host fish.
After feeding for about six days, it falls off into the substrate.
About five days later the worm's body ruptures and releases a new population of young worms, and the cycle starts again, but in larger numbers.
Symptoms to Look For

Once these worms start feeding on a host fish they acquire pigmentation, which causes the appearance of black spots about the size of a grain of salt on the body and fin membranes
Worms that freely move about on fish, the spots do not always remain stationary. On light colored fish they are easy to see, whereas on dark colored ones they may go unnoticed at first. Fish will scratch up against objects in an attempt to dislodge the parasites, and if allowed to progress the fish become lethargic, loss of appetite and colors occur, rapid respiration develops, and secondary bacterial infections can invade damaged tissue.

Answer 4

Sounds like a mold or fungal infection on the leaves. The wierd weather does that sometimes. When the leaves fall the infection will be gone and next year the tree will be fine.

Answer 5

It could be several things depending on where you are, most likely non-lethal; your best bet is actually to call your local county agricultural department or university cooperative extension. They have trained staff whose job is to answer questions like this, and if it's an important disease (like a new location of Sudden Oak Death) they'll want to know.

Answer 6

It is what is commonly refered to as TAR. It is an airborne fungal infection that is common to maple.

Answer 7

It could be dead parts of the leaves, or possibly caused by bacteria or a fungus. I'm sure its nothing to be concerned about.

Answer 8

Mayby its sick or its something natural 4 the tree.

Answer 9

try to wash it off because it may be just dirt or mold if it isnt get some fertilizer to put around its roots and it may help

Answer 10

Maybe skin cancer due to exessive sun exposure, try a sun block