Pyxine katendei
Pyxine katendei is a species of corticolous (rock-dwelling), foliose lichen in the family Caliciaceae. Found in East Africa, it was scientifically described as a new species in 1975 by lichenologists Dougal Swinscow and Hildur Krog. The lichen has a whitish to pale grey thallus that is tightly appressed to its substrate. The  comprising the thallus are somewhat convex; they lack pseudocyphellae (tiny pores for air exchange), and have sparse pruina. The thallus underside is black; the internal medulla is white. The lichen contains triterpenoid compounds as well as lichexanthone; the latter substance causes the lichen to fluoresce when lit with a long-wavelength UV light. Pyxine katendei is only known to occur in Ethiopia, Uganda, and Kenya, where it is common on trees and shrubs, typically in sunny locations, and at elevations ranging between . References

Caliciales
Lichen species
Lichens described in 1975
Lichens of East Tropical Africa
Taxa named by Hildur Krog
Taxa named by Thomas Douglas Victor Swinscow