[1] This corticolous (tree bark-dwelling) lichen is characterised by its pale olivaceous-brown thallus and its unique ascospores, which are surrounded by a wavy gelatinous sheath.

[2] Viridothelium sinuosogelatinosum was formally described in 2022 by the lichenologists André Aptroot and Marcela Eugenia Cáceres, as part of a broader study aimed at cataloging the lichen biodiversity within a small area of the Amazon rainforest.

The species epithet, sinuosogelatinosum, alludes to the distinctive wavy (sinuoso) gelatinous sheath that envelops the ascospores, highlighting one of its most distinguishing features.

[2] The thallus of Viridothelium sinuosogelatinosum is crustose (crust-like), corticate, and has a dull pale olivaceous-brown colouration.

The ascomata (fruiting bodies) are single, either globose or pear-shaped, measuring between 0.4 and 0.6 mm in diameter, and are black in colour.