Whilst on recording foray with Northwest Fungus Group near river Mersey in damp woodlands, I found a pyrenomycete growing on the bark of attached dead Salix branch.  The sulcate ostioles have the cross feature of Diatrypaceae; without green-yellow fluid on section( E. flavovirens), and no colour reaction with KOH. Asci are 8 spored without blue reaction around apparatus from Lugol's and the a.spores are mostly around 6 x 1 -15.mc, pale. I could see plenty of fine simple paraphyses which seemed to rule out sp such as Eutypa maura. I repeated the squash with Cotton Blue and this time some perithicia seemed to be without paraphyses though they were evident elsewhere on slide.  
Some texts disagree on presence of paraphyses in some of these species.
I had a look at the Salix associated species on this website but didn't seem to be one of those.  
Not even quite sure whether it be Eutypa or Diatrype though it does look like Diatrype bullata, but for the paraphyses. 

I do understand there is some fluidity amongst the taxonomy of this group. 

John Watt
Ormskirk,
England