Puccinia vincae on Greater Periwinkle
- This topic is empty.
-
Seen today, on plants within 200yds from home. Puccinia vincaeon Greater Periwinkle – Vinca majorSpore measurements averaging slightly larger than Wilson & Henderson’s details should suggest – but calibration has been checked and measurements are correct.
I went looking for this, knowing that the plants were only around the corner, to see if there was any sign of the
Puccinia vincaehaving been infected with the basidiomycete “ Tuberculina sbrozzii” – but couldn’t find any indication of its presence. Click on images to view at full size.
[attachment=3]Puccinia vincae on Vinca major leaves 030515.jpg[/attachment] Puccinia vincae– typical infection on both upper and lower leaf surfaces. 
[attachment=2]Puccinia vincae spores x400 dry.jpg[/attachment] Puccinia vincaespores x400 – mounted in air. 
[attachment=1]Puccinia vincae spores x400 030515.jpg[/attachment] Puccinia vincaespores x400 – mounted in water. 
[attachment=0]Puccinia vincae spores x400 measured 030515.jpg[/attachment] Puccinia vincaespores x400 – mounted in water – with measurement details. Regards,
Mike.
Hi when telia appear have a good look under oil. All the books etc. I have seen talk of the teliospores being warted – e.g.
Wilson & Henderson“with verrucae arranged in irregular longitudinal lines”. I contend that the ornamentation is of
pitsnot bumps. If you look at the image at top right you can see that the ‘shadow’ which Normarski contrast gives you is as if lit from approximately the “south-west” (easily seen on the spines on the urediniospores). Carry that on to the ornamentation on the teliospores and if they were raised then they too should be lit at their SW edges – they’re not; but if they are like craters then their being lit at the NE makes sense. Also if you look at the outline of the teliospores it’s relatively smooth – not with numerous raised “bumps”. The analogy I use is a peanut shell – the depressions do not show on the profile.
Finally I think the arrowed portion of edge shows pits pretty well.
I can see why people have been confused – it’s like those optical illusions where you can’t tell if an image of a face is convex or concave; but I’ve looked at these spores long and hard and that’s what I (and others I have spoken to after showing them these images) now think. “Rustbucket” has kindly sent me an image of this species from Tom Preece’s book with SEM’s of UK rusts and the same think can be made out there.
[attachment=0]Pucvin0a.jpg[/attachment]
So a good test for setting up your ‘scope for maximum resolution
cheers
Chris
I have been studying a collection of Puccinia vincaethis evening and just wanted to say that I agree the teliospores look like peanuts. You provided me with the motivation to fiddle around with oil immersion and a bit of focus-stacking, so I thought I would share the result 
I think I also have
Tuberculina sbrozziiparasitising my collection of Puccinia vincae. I’ve posted photos and micrographs here: https://misidentifyingfungi.blogspot.com/2023/04/rusty-threefer.html ” class=”bbcode_url”> https://misidentifyingfungi.blogspot.com/2023/04/rusty-threefer.html I’ve never heard of
Tuberculina sbrozziibefore and I haven’t found much about it via the old ‘Google search’ technique. Can I record my collection as such? Or have I stumbled into something that’s more complicated than I’ve bargained for?
- You must be logged in to reply to this topic.