Aggregatorygma lichexanthonicum is a species of corticolous (tree-bark dwelling), crustose lichen in the family Graphidaceae.

The type specimen was collected by the author in Reserva Cristalino in Mato Grosso, Brazil, at an altitude of 250–350 m (820–1,150 ft); there, it was found growing on tree bark within a primary rainforest.

[1] The thallus of Aggregatorygma lichexanthonicum is crustose and continuous, extending up to about 20 cm (8 in) in diameter and up to 0.1 mm thick.

Ascomata (fruiting bodies) are superficial on the thallus, sessile with a constricted base, initially solitary but soon dividing into aggregates of linear, simple or slightly branched lirellae within a pseudostroma that is distinctly lobate in outline.

[1] Chemical analysis reveals the thallus to be UV+ (yellow) and the disc UV+ (bluish white), with spot tests for C, K, KC, and P being negative.