Lentithecium fluviatile  

Conidial morph: not known.
Ascomata 180-210 µm diam., 180-200 um high, subglobose to globose, immersed, black, clustered in small groups or short rows, each with an inconspicuous central black papillate ostiole; clypeus black, of dark brown hyphae 1-1.5 µm diam. Peridium 20-25 µm thick, composed of carbonaceous thick-walled polygonal cells, surrounded by hyaline hyphae. Interascal tissue of cellular pseudoparaphyses, numerous, 3-4 µm diam., degenerating at maturity. Asci 107-130 x 23-28 µm, broadly clavate, shortly stipitate to almost sessile, thick-walled and fissitunicate, broadly rounded at the apex, 8-spored. Ascospores arranged biseriately, 25-28.5 x 9-10.5 (-11.5) µm, broadly fusiform to clavate-fusiform with rounded ends, 1- to 3-septate; the primary septum submedian, the second cell from above slightly swollen; constricted at the septa, mainly the median septum, hyaline, sometimes browning with age, surrounded by a broad expanding gelatinous sheath, to 5 µm thick, not constricted around the septa.

Description in part adapted from Van Ryckegem & Aptroot (2001).