On Living Ivy

[Chris Johnson]

I brought this branch back as it was covered in tiny (100-200 µm) perithecia.

I initially set it for spores and got some which fit well with Diaporthe hederae, but little else does. I then tried a section but they were too small so I but 3 on a slide and was surprised to have 3 different results. The first matched the spores dropped. The second was a mass of conidia, and the third produced banana-shaped spores.

At a total loss - I will post each separately for clarity and to spread the images.

[Chris Johnson]

Second:
Conidia 7.5-9.0 x 2.9-3.6 µm

[Chris Johnson]

Third:
Spores 20.4-26.7 x 2.5-3.1 µm

[Chris Yeates]

Hi Chris
These pages from Grove's Stem & Leaf Fungi vol. II may cast some light on the middle (and possibly the first) one. Am I correct in thinking that what I am seeing in the third one are asci with elongate spores?

[Chris Johnson]

Thank you Chris, that is a big help.

You are correct regarding the final two images. One in water, t'other in Lugol's.

Regards, Chris

[Paul Cannon]

Sorry, have come to this rather late. Nothing much further to add regarding the first two species, but I think the third could be Vialaea insculpta. This has isthmoid ascospores (looking like two bananas in a chain) and can break up at the constricted part. However, the spores do look slightly narrow, it would be worth re-examining to see whether the spores are actually like this. More info in FGBI.

Best wishes
Paul

[Chris Johnson]

Hello Paul - bit late with this as I've been on Skye for a few days.

I looked closely at the time and didn't see anything that would suggest Vialaea insculpta, but note the similarity. Also, the ascomata were more superficial than images I've seen of Vialaea insculpta, especially Jenny's.

One to look out for and thanks for your thoughts.

Regards, Chris