Pyrenula cryptothelia is a species of corticolous (bark-dwelling) crustose lichen in the family Pyrenulaceae. It has a neotropical distribution.
Pyrenula cryptothelia was originally described by the Swiss lichenologist Johannes Müller Argoviensis in 1885 as Pyrenastrum cryptothelium. The species has undergone some taxonomic changes: first described as Pyrenastrum cryptothelium, then transferred to Astrothelium by William Nylander in Auguste-Marie Hue's "Nouvelles Archives du Muséum d'Histoire Naturelle" (1892), and finally placed in the genus Pyrenula as Pyrenula cryptothelia in 2003.
Pyrenula cryptothelia is characterized by , partly fused ascomata (fruiting bodies), typically occurring in groups of three or four. It has large spores measuring 32âÂÂ37 by 13âÂÂ15.5 üm with three eusepta; a later review of the genus gives a broader spore length range, 30âÂÂ45 üm. The species is morphologically similar to Pyrenula cubana, but can be distinguished by its larger spores, as P. cubana has spores measuring 21âÂÂ25 by 8âÂÂ10 üm.
Pyrenula cryptothelia has been documented in Cuba (type locality), Ecuador (Napo Province and Los RÃÂos Province), and Panama (Veraguas Province, Bahia Honda, Isla de Canales de Tierra).