[2] The genus was circumscribed by Swiss botanist Augustin Pyramus de Candolle in 1805, with Roccella fuciformis as the type species.

These branches has colours ranging from creamy white-greyish to greyish-brown and have surfaces that are either smooth or wrinkled, with some being sparsely pruinose (powdery) or lacking pruina (epruinose).

The medulla (the inner layer) is loosely structured above, having a byssoid (fibrous) or chalky texture, and below it becomes plectenchymatous (tightly packed cells) near the basal plate (holdfast) area, often showing a (yellowish) brown colouration.

[4] The epithecium (upper layer of the ascomata) is about 40 to 50 μm high, brown, with intertwined paraphysoids (supporting structures in the hymenium) that are sparsely branched.

[4] Conidiomata (asexual reproductive structures) are pycnidial (flask-shaped), solitary, immersed in the thallus, and black, measuring about 0.1 mm in diameter.