Mycelium immersed, intracellular within the host hyphae, branched, ca 2 µm diam, hyaline, the infected host tissues purplish brown.
Anamorph: conidiomata absent. Conidiophores in dense colonies giving a grey-brown felted appearance to the host surface, short, composed of one or a few cells, superficial. Conidiogenous cells not distinguishable morphologically from the conidiophore, terminal, proliferating percurrently. Conidia 7-8 x 3.5-4 µm, cylindrical to barrel-shaped, dark brown, smooth, 1-celled, rarely 2-celled and then measuring 11-14 x 3.5-4.5 µm, forming loose chains, easily separating.
Teleomorph: not known.
Taeniolella beschiana occurs on species of Cladonia subgenus Cladonia. It has a less felty macroscopic appearance, and has slightly verrucose rather than smooth conidia.
Parasitic on lichens belonging to Cladonia subgenus Cladina, discolouring the host thallus. In GB&I, reported from Cladonia arbuscula, known elsewhere also on C. portentosa and C. stygia.
In GB&I, reported from Scotland (Ayrshire, Moray, Orkney Is). Also seen in Austria, Czech Republic, Denmark and Estonia.