Astrothelium flavostiolatum
Astrothelium flavostiolatum is a species of corticolous, crustose lichen in the family Trypetheliaceae. Found in Ecuador, it was formally described as a new species in 2016 by Dutch lichenologist André Aptroot. The type specimen was collected by Harrie Sipman from the Reserva Biológica San Francisco in the Andes of southern Ecuador at an altitude of ; there, it was found in a rainforest growing on smooth tree bark. The lichen has an olive-green thallus with a cortex but lacking a prothallus, covering areas of up to in diameter. The thallus is covered with small wart-like structures, and consists of swollen and distended areas that coalesce, forming a continuous structure. The presence of the lichen does not induce the formation of galls in its host. A yellow anthraquinone is the only lichen product that was detected from the species using thin-layer chromatography. The group of characteristics of the lichen distinguishing it from others in Astrothelium are its irregular, thallus; its solitary to confluent ascomata with yellowish ostiolar rims, and the coarse thallus verrucae.