[2][3] It comprises the single species Pseudoleptogium diffractum, a saxicolous (rock-dwelling) crustose lichen that grows on calcareous rocks.

[4] The genus was resurrected and redescribed in 2014 as part of a molecular phylogenetics-informed reorganisation of the family Collemataceae, the jelly lichens.

[5] The thallus of Pseudoleptogium is made up of tiny to small squamules (scale-like structures) that range from 0.5 to 1.0 cm in diameter.

In the centre of the thallus, the squamules are much smaller, resembling tiny, convex lumps (areoles) that are 0.1 to 0.3 mm across.

[5] The overall colour of the thallus is brownish-olive to black, and the surface of the squamules has a wrinkled and glossy texture, particularly at the tips.