Caution: Do NOT use iSpot to identify fungi to eat!
Some fungi are very poisonous so a mistaken ID could have serious consequences.
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See www.ispot.org.uk/node/296158 for photos of infected leaves.
Thanks - much appreciated.
Martin, how did you capture them? Trinocular adaptors + regular camera or C-mount + digital microscope camera or something else?
Edit: I would agree, but I know nothing about Phragmidium under the 'scope!
I have a good microscope though I'm far from being good at getting the best from it. I have a camera that replaces one of the eye-pieces and captures images. However it doesn't work on my new PC - acquired after the old one packed up. I've just taken delivery of a £25 refurbished Pentium 4, XP computer that I'm hoping with mean I can use the fancy camera again. In the meantime, these images were captured by pointing my point-and-click Fuji F80EXR (highly recommended pocketable with 10x optical zoom - £77 from Amazon at the moment) down the microscope and, well, clicking. The images were then trimmed and adjusted with Paint Shop Pro. Google Phragmidium violaceum and you will quickly become an "expert" (like me lol) and, in particular, compare and contrast my images with those at
Your 2nd photo shows 4-5 septa, and Google declares that P. violaceum is mostly 3-septate, and suggests Phragmidium bulbosum as a possibility. That's Google for ya.
I found a Key to Phragmidium species in Bulgaria (http://www.mycobalcan.com/FT_1_2_04.pdf), which includes the following:
Teliospores 2-5-celled, mostly 4-celled; wall 5-6 μm thick, with a papilla up to 7 μm long. Aeciospores echinate; wall 3.5-4 μm thick --> Ph. violaceum
Teliospores 3-7-celled, mostly 6-celled; wall to 5 μm thick, with a papilla up to 16 μm long. Aeciospores echinate or
verrucose, wall 1-2 μm thick --> 10
Aeciospores verrucose, urediniospores echinate. In swelling both of them formed cameras around the pores. Teliospore wall
4-5 μm thick --> Ph. bulbosum
Aeciospores and urediniospores echinate. In swelling not formed cameras around the pores. Teliospore wall 3-4 μm thick --> Ph. acuminatum
My specimen has 4-6 cells, mostly 5-celled, from which I'd say it is less likely to be Ph violaceum but more likely is Ph bulbosum or Ph acuminatum.
P. acuminatum is extinct in the UK, so possibly P. bulbosum.
I found some examples of the "real" Ph violaceum yesterday - with mainly 4-celled teliospores and violet spots (big clue!). I'll post it later. In the meantime, I reckon this one must be Ph bulbosum. By the way, where could I find reference to the absence of Ph acuminatum in the UK?
... this link.
It's awkward when microscopic characters fall in the grey area, but I'm with you on P. bulbosum. Unless my eyes deceive me, there appears to be a 7-celled spore in your photo. Going off your key, measuring the papillae (the 'noses') might allow more confidence.
Microfungi on Land Plants by Ellis & Ellis is one specialist book in this area, but it's a whopping £60.
I'm not quite in business for measuring via the microscope after my old computer packed up, but should be soon. Thanks for the book details. The upper surfaces of this specimen certainly didn't show the violet spots which I've now seen elsewhere... though I know such easy characters can be misleading.
See http://www.ispot.org.uk/node/297392 for the real Ph violaceum.
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