Pyrenula abditicarpa is a species of corticolous (bark-dwelling), crustose lichen in the family Pyrenulaceae. Found in Brazil, it is characterised by ascomata that are deeply immersed in the bark beneath the thallus, with distoseptate ascospores measuring 50âÂÂ55 üm by 23âÂÂ25 üm. The species was first identified from a specimen collected in the Serra de Itabaiana National Park, Sergipe, Brazil, at an elevation of approximately .
The thallus of Pyrenula abditicarpa is thin, , olive brown, and smooth, closely adhering to the rough bark of trees. It lacks pseudocyphellae and a prothallus. The ascomata are , measuring 0.6âÂÂ0.8 mm in diameter and 1âÂÂ2 mm deep, with a wall and a pale brown, depressed ostiole. The is not with oil droplets. The are irregularly , brown, and both and , with rounded . No pycnidia have been observed. Chemically, the thallus does not react to ultraviolet light, and no lichen products were detected using thin-layer chromatography.
Pyrenula abditicarpa is found on smooth bark in undisturbed Atlantic rainforests and is only known from Brazil. This species is notable for its deeply immersed ascomata and mid-sized muriform ascospores, which distinguish it from others within the genus Pyrenula.