Salut à tous,

I collected some perithecia on Carpinus betulus petioles on 19th June in Southern England that I would like some help with...

Perithecia 100-150 µm diam, with long necks up to 270 µm, each surrounded by a white collar

Ascospores 19.7-25 x 2.6-3.2 µm, with one median septum. I think I can see appendages in water on immature spores, but they disappear too quickly to photograph!

Asci IKI-, Congo red +

I found Alain's key to species on Carpinus leaves here on Ascofrance, with which it keys out relatively easily to C.amoena, though my spores are a little long.

I cross-referenced with Leaf-inhabiting genera of the Gnomoniaceae, Diaporthales Sogonov, Rossman et al, and all seems OK, again apart from the spore length (there is no detailed description there).

Can anyone confirm my thoughts that this is C.amoena, or perhaps offer a suitable alternative?

Does anyone have access to Sodov's description in Monographie taxonomique des Gnomoniaceae. Beihefte sur Sydowia 9: 1–315. (1983)?

Amitiés,

Nick

Alain GARDIENNET, 27-06-2014 07:52

Re : Gnomoniaceae on Carpinus petioles

Hi Nick,

Happy to see my key useful.

Yes it's exactly G. amoena. Length up to 25 µm is not impossible, to my mind.

The most important in all features is that you show white collar around the neck. You also should  observe necks > 300 µm long.

If you see appendices on young ascospores, appendices are present. It's ok.

I've never seen this fungus unfortunately.

Alain

Björn Wergen, 27-06-2014 16:14

Re : Gnomoniaceae on Carpinus petioles

Hi Nick,

you can send me the collection or, if you wish, you can send me the photos, which are really good for FP :)

Nice finding.

regards,
björn