Bonjour,

On m'a confié cette récolte fort intéressante que je n'ai pas su déterminer. Même pas le genre.
Merci d'avance pour votre aide ! J'ai oublié de tester l'acide lactique. Les spores me paraissent très finement striées (difficile à voir).

On unidentified ascomycete (Cryptostroma corticale ?), on branch of Acer sp.

Ascomata perithecial, gregarious, clustered in large groups, widely obpyriform, 130-170 um high, 110-140 um wide, laterally pinched when dry, brown, not turning in 3 % KOH. Ascomatal wall smooth, 23-25 um thick, composed of two regions: outer region 17-19 um thick, composed of subglobose to ellipsoidal, thick-walled cells, with brown wall ; inner region 4-7 um thick, composed of elongate cells, with hyaline wall. Asci unitunicate, subcylindrical, short-stipitate, 8-spored, apices rounded and simple, uniseriate. Ascospores narrowly ellipsoidal, 11-15 x 2,5-3,4 um, 1-septate, often constricted at septum, smooth then finely striate, thick-walled, hyaline.