Glyphis frischiana

Glyphis frischiana is a species of corticolous (bark-dwelling) script lichen in the family Graphidaceae. It is distinguished by its large, single-spored asci, and the presence of stictic acid as a major metabolite. Found on the trunk of Eucalyptus trees in Cameroon, it is similar in appearance to Glyphis atrofusca but can be distinguished by these key characteristics.

Taxonomy
Glyphis frischiana was first formally described as a new species by German lichenologist Klaus Kalb in 2020. The type specimen was collected in Nkwentang Village, Ndu Subdivision (Donga-Mantung, Northwest Region). It was found on the trunk of a Eucalyptus tree in a small plantation, at 1950 m above sea level. The specific epithet, frischiana, was chosen to honour Dr. Andreas Frisch, an expert in Ostropales and Arthoniales, who collected the type during his PhD studies.

Glyphis frischiana belongs to the subgenus Pallidoglyphis within the genus Glyphis, along with G. atrofusca and G. substriatula.

Description
The thallus of Glyphis frischiana is corticolous, with a thin, smooth, and surface. It appears dull and is partly, with the densely filled with clusters of crystals. The thallus is approximately 75 μm thick. Ascomata are to sessile, with a thick lateral margin and can be up to 4 mm long and 0.5 mm wide. They are straight, curved, or and may be simple, trifurcate, or irregularly branched. The is black and distinctly visible from above, while the  is open and brown to dark brown. The is laterally  and hyaline to brownish at the base.

The hymenium is 110–150 μm high and clear, with a, light to dark brownish. The is hyaline, and the paraphyses are thin, surrounded by a thick jelly. are hyaline, becoming very slightly brownish with age, densely, measuring 55–110 by 28–35 μm, and iodine-positive brownish-blue or violet-blue.

Glyphis frischiana contains stictic acid as its major secondary metabolite, with constictic acid and menegazziaic acid present in minor amounts.

Similar species
Although it may easily be confused with a Graphis species, Glyphis frischiana can be distinguished by its brown, potassium hydroxide-negative epithecium and thick-walled paraphyses embedded in a jelly. When compared to Graphis streblocarpa, Glyphis frischiana differs in the absence of a brown, convergent , and a non-visible disc.