Hanstrassia is characterised by a predominantly areolate and sorediate thallus, distinguishing it from its close relative Elenkiniana.

It is a member of the Mikhtomia sensu lato clade of the subfamily Caloplacoideae, which also contains the genera Laundonia, Opeltia, and Oxneriopsis.

The areoles are relatively thick, with soralia that are scarce to numerous, labriform in shape, and typically located along the margins.

The cortical layer of the thallus is either pseudoprosoplectenchymatous or scleroplectenchymatous, while the medulla is dense, made of interwoven hyphae lacking clear orientation.

[2] In terms of chemistry, Hanstrassia species predominantly contain the anthraquinone substance fragilin and the depsidones compounds caloploicin and vicanicin.

These species typically grow on limestone and calcareous schist, favouring the vertical cliffs in areas characterized by dry continental climates.