Chère collegues,

I have found this small Diaporthe species on dead attached Salix twix with single growing perithecia, embedded in the bark and with 0,1-0,3 mm diam. Microscopically I think it should be a member of the genus Diaporthe, but I am not sure what it is exactly (D. rudis for example has similar spore size and shape, but grows on other substrates). 

It has also similarities with D. alnea, described in Breitenbach&Kränzlin, Vol 1, which seems to have Alnus on the top of its priority list. 

Perhaps you have an idea ;)

I have probably seen very inconspicuous appendixes on both endings.

regards,
björn