Protothelenella

Protothelenella is a genus of fungi in the family Protothelenellaceae. It contains 11 species, some of which form lichens. Protothelenella species have a crustose thallus with spherical to pear-shaped, dark brown to blackish . Microscopic characteristics of the genus include asci with an amyloid , and that are colourless and contain multiple internal partitions. Some species grow on acidic including rocks, soil, bryophytes, plant detritus or rotten wood. Other species are lichenicolous (lichen-dwelling), growing on species of Solorina, Peltigera, Pseudocyphellaria, or Cladonia.

==Taxonomy== The genus was circumscribed by Finnish lichenologist Veli Räsänen in 1943, with Protothelenella reducta assigned as the type species. The genus Thelenella is similar in some aspects, but differs in the negative iodine staining of its ascus and hymenial gel.