Astrothelium trematum

Astrothelium trematum was formally described by lichenologists Klaus Kalb and André Aptroot in 2018. The type specimen was collected near Caraguatatuba, São Paulo, Brazil, in a plantation of Theobroma cacao. The specimen was collected by the first author on 9 March 1980. The specific epithet trematum refers to the distinct ring around the ostiole that separates the ostiole from the thallus. ==Description==

The thallus of Astrothelium trematum is dull, up to 0.3 mm thick, and pale olivaceous green, with a thick and a containing hyaline crystals. It is not surrounded by a . Ascomata are spherical to , 0.6–0.9 mm in diameter, solitary in warts. The is low hemispherical, almost completely covered by a thallus layer, about 1–1.5 mm in diameter, and without pigmentation. Ostioles are apical, consisting of exposed , black ascoma wall, about 0.2 mm wide, surrounded by a whitish ring of approximately 0.3 mm in diameter. The is not . number eight per ascus, and are hyaline with 5 to 7 septa, measuring 95–135 by 25–33 μm. They have a long ellipsoid shape with internal diamond-shaped . were not observed. The thallus of Astrothelium trematum is UV−, C−, K−, KC−, and P−. Thin-layer chromatography analysis did not detect any secondary metabolites. ==Habitat and distribution==

Astrothelium trematum was found on tree bark in a cocoa plantation, and at the time of its original publication, was known only to occur in Brazil. ==References==