[1] This lichen species is closely related to Astrothelium subclandestinum, but differs in its hamathecium, which is not inspersed.

The species is closely related to Astrothelium subclandestinum, which has an inspersed hamathecium.

[2] The thallus of Astrothelium supraclandestinum is corticate, smooth to somewhat bullate, somewhat shiny, continuous, and greenish-grey, covering areas up to 7 cm (2.8 in) in diameter.

[2] Ascomata are pyriform, measuring about 0.5–0.8 mm in diameter, and are mostly aggregated in groups of 2–5, immersed in the bark tissue below pseudostromata.

[2] Astrothelium supraclandestinum is found on smooth bark of trees in primary forests.