The genus was circumscribed in 2013 by Patrik Frödén, Ulf Arup, and Ulrik Søchting, with S. elegantissima assigned as the type species.

S. testudinea specimens frequently feature isidia, specialised outgrowths that aid in vegetative reproduction.

[3] From a chemical perspective, Stellarangia falls into the A3 chemosyndrome, indicating a distinct set of secondary metabolites associated with the lichen.

[3] Stellarangia is part of lichen communities found in unique habitats beneath rocks (hypolithic) in the Namib Desert, which provide special microclimatic conditions conducive to their growth.

They display an inverted morphology as an adaptive mechanism to high irradiance and low water availability in desert soils.