Hi everyone,

Maybe someone can help me to identify this pyreno growing on leaves. Below I attach photos of the specimens as well as some data and a file with information about the microscopy.

As I refer in the data I did not observe any ascus; Not because I did not look for them, but because I was not able to see one in the several slides prepared. The result was always the same: either the perithecia were empty (dead) or had a amount of spores near the ostiole and, pressing the slide, a big amount of spore were ejected but no asci was visible. I have tried to key it using the two keys in the references, prepared for lichens, which maybe is not the case, since no alga was found: In [1] the only genus with simple spores considered is Monoblastia, which has bigger spores ornamented with spines; From [2] I end up with Verrucaria, whose key is prepared for crustose species on rocks and no species is mentioned living on bark or leaves.

So, any help on the classification/identification of this pyreno will be welcome. A genaral key for pyrenomycetes will also be appreciated.

Thanks in advance,
zaca

Data:
Date: 2015-07-18
Location: Mata do Bussaco, Portugal
Ascomata: Pyrenocarp without involucrellum, with exciple pigmented throughout, and the periathecia covered by a thin layer of bark cells;
Asci: Not observed;
Ascospores: Simple and guttulate, from one to several drops, with dimensions
(9.1) 9.6 - 11.7 (13.1) x (6.1) 6.2 - 7.6 (8.3) µm
Q = (1.1) 1.3 - 1.8 (2.1) ; N = 35
Me = 10.7 x 6.9 µm ; Qe = 1.6 .

References:
[1] André Aptroot, Robert Lücking, Harrie J.M. Sipman, Loengrin Umaña, José Luis Chaves;
Pyrenocarpous lichens with bitunicate asci – A first assessment of the lichen biodiversity inventory in Costa Rica; Bibliotheca Lichenologica Band 97, 1-162 (2008).

[2] Smith et al. (eds.), The Lichens of Great Britain and Ireland, The British Lichens Society, 2nd ed., 2009.

Luc Bailly, 25-07-2015 11:30

Re : 2015-07-18-9407 Pyreno on leaves

Hello Zaca,

Don't search for any ascus, there is none: it's a coelomycete, an anamorph, probably a Phoma or close to to it from the shape of conidia's.

I guess it grows on Quercus leaves, right? Quercus ilex? Quercus suber?

Cheers - LUC.

Luc Bailly, 26-07-2015 10:18

Re : 2015-07-18-9407 Pyreno on leaves

Hi Zaca,
The important characters are the hosts (some species are plurivorous, others are specific to hosts), the size, shape and guttules of conidia's, and a look at the hymenium (that's poorly differenciated on Phoma, more noticeable on some other genera).

You can begin with Grove: British stem and leaf fungi 1 & 2, available on Cyberliber: http://www.cybertruffle.org.uk/cyberliber/books.htm and papers published in the earlier issues of Persoonia also available on Cyberliber, several articles, check for Phoma-related articles: http://www.cybertruffle.org.uk/cyberliber/61056/index.htm

And there's of course the book: Ellis, M.B. and Ellis, J.P., Microfungi on Land Plants.

With that, it's a good beginning, but researches are going on, Phoma is a difficult genus in the sense there are many, many species which sometimes need to be redescribed.

Cheers - LUC.