Black spots

accipter · #1 (**permalink**) 04-10-2010, 01:58 PM

Can anyone tell me what the large black spots on sycamore leaves are please. Alan.

The Woodman · #2 (**permalink**) 04-10-2010, 02:52 PM

Tar spot disease - Rhytisma acerinum

A very common fungal pathogen of sycamore and maple. Nothing to be worried about - they live with it.

Dorts · #3 (**permalink**) 04-10-2010, 02:54 PM

It's called Tar Spot - Rhytisma acerinum . It is a common fungus which attacks the leaves of Sycamore and other Maples in the autumn and helps to rot them down.
Dorts.

accipter · #4 (**permalink**) 04-10-2010, 03:01 PM

Thanks very much, has this disease been around for some time then? I have only just noticed it.

Dorts · #5 (**permalink**) 04-10-2010, 03:05 PM

Quote:

Originally Posted by accipter

Thanks very much, has this disease been around for some time then? I have only just noticed it.

Probably for as long as Sycamores have been around: a very long time; maybe 50+ million years!
Dorts.

accipter · #6 (**permalink**) 04-10-2010, 03:19 PM

O dear I feel very bad now' still better late then never.

pobjoy7 · #7 (**permalink**) 05-10-2010, 08:16 PM

Tar spot on Sycamore is a recent phenomenon for Northern folk. Until the smokeless zones started in the 1960's all the smoke and sulphur in the air killed this fungus and the leaves were free of it.

Sycamores haven't been a common tree for long in this country, possibly only 400 years as 'common'. They seem to be looking worse for wear lately and don't like these droughts we keep getting. The tar spot doesn't help the tree and by Autumn the tree seems glad to get rid of the crispy leaves. I wonder if the species is on its way out in some areas. Grey squirrels love to kill young Sycamores by chewing the bark off.

accipter · #8 (**permalink**) 05-10-2010, 09:42 PM

On the Way out its funny you should say that this year it looks really bad.

Dorts · #9 (**permalink**) 05-10-2010, 10:04 PM

There is still a lot of debate as to the Sycamore being native or not.
Some say it is, others say it was brought here by, yes you've guseed it: the Romans, but many believe it to be a fairly recent introduction, perhaps around the 1700's.
It is a fine tree that has done extremely well here. If given the oppotunity it can mature into as fine a specimen as any other. But generally we think of it as that nuisance tree that seems to root itself just about everywhere and anywhere, or the 'weed of the forest'.
With the potential demise of the beech and oak perhaps following the way of the elm, we may become thankful we have a tree like the sycamore to perhaps take their place in the woodland; better that than nothing. And this is already happening in many places.
In my opinion the sycamore is here for a very long time yet and I have no problem with that.
Dorts.