I'd like to know your opinion about this (I think) Anthostomella species growing on small branches (20 mm broad) of Fraxinus excelsior lying on the ground, at the sea level (Botanical Garden of Gijón/Asturias/Spain).

The inmersed, gregarious, blackish, roundish or elliptical perithecia, 1.20-1.35 microns in diam., are singly, in pairs or small groups just beneath the bark with only the short necks protruding. Many times an stromatized blackish clypeoid structure is present over the perithecia.

Asci cylindrical, 145-155 x 7.5-8,5, unitunicate, with an apical cylindrical apparatus up to 3 microns long, deeply blueing in IKI, with 8 more or less uniseriate 2-celled ascospores that seem to have very small caps at the poles (that are not well visible in china ink). These ascospores, close to those of A. rubicola, are allways hyaline or only a few of them at most slightly brownish inside the asci.

I don't know any species that fits with my fungus

Have you any idea?

Thanks again

Jacques Fournier, 13-03-2015 18:51

Re : Anthostomella on Fraxinus

Hola Enrique,
I have seen two collections of your fungus from France, one on Quercus ilex twigs collected by Paul Leroy, the other one on Acer twigs by C. Lechat. Very few ascospores develop a pale brown cell lacking a germ slit, just like in A. rubicola. Likely an undescribed lignicolous counterpart of A. rubi, as you suggested. Frustrating.
Cheers,
Jacques

Enrique Rubio, 13-03-2015 18:59

Re : Anthostomella on Fraxinus

Thanks again, Jacques

There exists some pyreno that you have not seen? I think not...

My material will be keeped in my herbarium. Maybe you will need it...

Enrique Rubio, 13-03-2015 19:22

Re : Anthostomella on Fraxinus

Hi Jacques

How did you describe the small polar caps of the ascospores? Had your spores these elements?

 

Jacques Fournier, 13-03-2015 19:30

Re : Anthostomella on Fraxinus

they apparently vanish at dry state, I did not see them in Indian ink on the material I have.
An important differential character from A. rubi migght be the tendency to cluster in small groups and to have well differentiated papillate ostioles.
Jacques

Enrique Rubio, 13-03-2015 19:37

Re : Anthostomella on Fraxinus

It is possible, Jacques. But I have studied them in fresh condition and in indian ink without success

Jacques Fournier, 13-03-2015 19:41

Re : Anthostomella on Fraxinus

I did not see them in water either, this is why I tried India ink.

Enrique Rubio, 13-03-2015 19:44

Re : Anthostomella on Fraxinus

I think is water the best way

Jacques Fournier, 13-03-2015 19:52

Re : Anthostomella on Fraxinus

OK you won!
Jacques