brown spots on maple leaves

[John]

I have a newly planted maple tree (not sure what kind) from a nursery that has brown spots on just about every leaf. The tree is about 10 feet tall. I'm in central Virginia and the tree is way out in the country about 30 feet from a pond in an open field. The following links show a typical leaf from this tree with a couple of shots I was able to take through a microscope. The brown spots are mostly circular with very small black bumps. I was not able to detect any critters or other moving objects on the leaf. Does anyone know what these are and if the tree is in trouble? I'm sorry if I'm not providing any obviously critical info, but I know little of the plant kingdom.

whole leaf:

(87k) (81k)

close-up:

(50k) (45k)

Thanks in advance,

John

[Vox Humana]

We have had an unusually cool, wet spring and the maples here (Cincinnati) are exhibiting sighs of fungal disease. Your tree probably has anthracnose. It shouldn't be fatal to the maple, although it will kill native dogwoods (cornus florida). Here is a link with some pictures:

[John]

anthracnose.

Vox,

After looking at the pictures and the descriptions, I'd lean toward Phyllosticta (Phyllosticta minima), because of the black dots that are clear in the pictures I took. I also found this description of Phyllosticta from another site

on infected leaves are brown with surrounding purple borders. They may be circular or irregular in shape and 5-10 mm in diameter. Tiny black fruiting bodies are scat- tered over the surface of the spots. Occasionally, the dried-up central portions of the spots crack and fall out before the end of the summer.

Here's another picture of Phyllosticta minima from another site that looks very much like what my tree has:

[Vox Humana]

(Cincinnati)

> Thanks Vox,

> Spots on infected leaves are brown with surrounding purple borders. They may

Occasionally,

You're probably right. I didn't look too closely at your pictures. The problem here is probably phyllosticta also, although anthracnose is pandemic in this area. My neighbor brought over some maple leaves last week with what looked like phyllosticta and my sycamore definitely has anthracnose.

[Mike LaMana]

Tar spot - cosmetic fungal disease. No worries. Let it go.