The type was collected by colleague Hiroyuki Kashiwadani in the Saylla District (Cuzco Province), where it was found in a pasture on the side of a road, growing on a calcareous rock at an altitude of about 3,200 m (10,500 ft).

[1] The lichen has a foliose (leafy) thallus that is greenish-gray in colour, with a tight attachment to its substrate.

Like all species of Punctelia, P. diffractaica has minute pores – pseudocyphellae – that help facilitate gas exchange.

In the type specimen, most of the apothecia (sexual reproductive organs) were juvenile, measuring less than 2 mm in diameter, and not reported in the description.

[1] Diffractaic acid is in the class of compounds called depsides, and has been scientifically investigated for biological properties such as antioxidant, antiulcerogenic and gastroprotective effects.