[3] The genus Immersaria presents with a crustose (crust-like) thallus that has shades ranging from yellow-brown, red-brown, orange-brown to simple brown.

The edges may be dusted with a fine, white powder (pruinose), and the areolae (small cracked segments) can merge around a black base layer (prothallus), creating larger patches.

The upper part of the thallus contains an orange pigment but lacks a lower cortex; instead, the core (medulla) is packed with grey granules.

[3] The apothecia (fruiting bodies) are of the lecideine type, meaning they are generally sunken into the thallus and can range from round to irregular in shape.

[3] Inside the apothecia, the hymenium (spore-producing layer) is colourless, with simple paraphyses (filament-like structures) that may branch rarely, with possible connections (anastomosing).