Endemic to the Falkland Islands, the lichen can be recognised by its sunken brown apothecia (fruiting bodies) and grey thallus with its distinctive paler margin.

The genus was named to commemorate the lichenologists Henry Imshaug and Richard Harris, who conducted extensive lichen collecting work in the Falkland Islands during the austral summer of 1968–1969.

[2] Phylogenetic studies place Imsharria as a distinct lineage that is basal to other major groups within Lecideaceae, separate from both Lecidea and Porpidia clades.

[2] Imsharria orangei forms a thin, whitish to blue-grey crust (thallus) on rock surfaces, typically only 0.1–0.2 mm thick.

The internal layer (medulla) is composed of loosely interwoven colourless filaments (hyphae) and turns violet when stained with iodine solution, a distinctive chemical reaction that helps identify this species.

[2] The lichen shows a strong preference for siliceous (silicon-rich) rock surfaces, particularly in two specific habitat types: stone runs and feldmark.

Stone runs are distinctive geological features in the Falklands consisting of large accumulations of broken rock fragments, while feldmark refers to sparsely vegetated rocky areas typical of exposed alpine environments.