The genus was circumscribed in 2018 by lichenologists Sergey Kondratyuk, Laszlo Lőkös, Ingvar Kärnefelt, and Arne Thell, with H. chilensis assigned as the type species.

The genus name Hosseusiella honours the German botanist Carl Curt Hosseus, who worked on the flora of South America.

[3] The thallus of genus Hosseusiella typically presents as small, crust-like to leaf-like structures that can form distinct rosette shapes with pronounced lobes around the edges.

Their colour ranges from yellowish-red or brownish-orange to dark reddish-orange or orange-yellow, often becoming paler towards the end of their lobes or isidia tips.

The lobes of these lichens spread out in a consistent pattern and can be closely attached (appressed) to the surface they grow on or might rise a bit, taking on a cylindrical shape.