Collemopsidium sublitorale  

Thallus immersed; photobiont in scattered groups or absent.
Anamorph: conidiomata pycnidia, often present, similar in form to the ascomata and only slightly smaller, with a black flattened involucrellum.
Teleomorph: involucrellum 200-400 (-1500) µm diam., lid-like, flat to slightly convex, with a broad slightly sunken ostiole. Ascomata 150-300 (-400) µm diam., subglobose to oblate. Ascomatal wall mid to dark brown, thin. Interascal tissue composed of fairly thick-walled branched and anastomosing pseudoparaphyses 1.5-2 µm diam. Asci 80-120 x 20-25 µm, clavate, short-stalked, thick-walled and fissitunicate with an extendible inner wall, 8-spored. Ascospores arranged biseriately, 18.5-20.5 x 8-9 µm, clavate, 1-septate with a slightly supramedian septum, hyaline, thin-walled, smooth, with a gelatinous sheath ca 1 µm thick.