Phragmidium? (On Dog Rose)

[Lancashire Lad]

Found this today, and think it might be Dog Rose Orange Stem Rust Fungus - Phragmidium tuberculatum or Phragmidium mucronatum.



Any confirmation/other will be much appreciated.

Regards
Mike.

[rich ard]

Originally Posted by Lancashire Lad

Found this today, and think it might be Dog Rose Orange Stem Rust Fungus - Phragmidium tuberculatum or Phragmidium mucronatum.

Any confirmation/other will be much appreciated.

I agree but I cannot remember which one it is more likely to be. You should be able to distinguish between the two by looking at the spore ornamentation under a microscope.

[Lancashire Lad]

Originally Posted by rich ard

I agree but I cannot remember which one it is more likely to be. You should be able to distinguish between the two by looking at the spore ornamentation under a microscope.

Thanks rich ard.

I don't have microscope equipment, so it might just have to be logged as Phragmidium sp. (Although from what I've just been finding on the net, it seems that P.tuberculatum may be more common).

Regards
Mike.

[rich ard]

Originally Posted by Lancashire Lad

Thanks rich ard.

I don't have microscope equipment, so it might just have to be logged as Phragmidium sp. (Although from what I've just been finding on the net, it seems that P.tuberculatum may be more common).

Regards
Mike.

I have since checked my jottings. I think the following was thanks to Malcolm Storey:

"Phragmidium mucronatum is far commoner, esp on R. canina. Phragmidium tuberculatum is more often on cultivated spp but you'd need to check details of the aeciospores under the microscope to be absolutely certain."

When I checked out this rust a couple of years ago on local 'wild' Dog Rose I found it all to be Phragmidium mucronatum



If you had a mscope this might be useful

Laundon: ADDITIONS TO THE RUST FUNGI OF . . .

richard

[Lancashire Lad]

Thanks for the information rich ard.
It was definitely on a wild Dog Rose, so it is likely, (on the basis of being more common), that it should be Phragmidium mucronatum.

But since we can't be certain without microscopy, It'll have to go down as just "probable".

Regards
Mike.