Phylogenetic analysis shows that the genus is in the large Sirenophila-Teloschistopsis-Halophila subclade of the subfamily Teloschistoideae (family Teloschistaceae).

[3] Elixjohnia is characterised by a thallus that is typically zoned, presenting initial appearances of brownish or a dirty greenish yellow in sterile circles.

Their disc is often a brownish-orange or yellowish-brown shade, sometimes with hints of red or even transitioning to a dull orange or a bright scarlet.

Finally, the conidia, or asexual spores, are broad and either ellipsoid or bacilliform, with measurements typically falling between 2–3 by 1.2–1.7 μm.

[2] Elixjohnia species predominantly colonise exposed coastal rocks, including quartzite, granite, basalt, and dolerite.

Additionally, they often share their habitat with species from various genera, including Tarasginia whinrayi, T. tomareana, Sirenophila eos, Jackelixia ligulata, Gondwania sublobulata, and Caloplaca conranii.