The lichen was first formally described by the botanists Joseph Dalton Hooker and Thomas Taylor in 1844, from specimens collected in Van Diemen's Land (now Tasmania), Australia.

This variety, identified in Victoria, Tasmania, and New South Wales, differs from the typical form of the species in having larger, clearly almost cylindrical lobes.

They are sparsely branched and range from flat to slightly curved upward (caniculate) on top, while being loosely attached (adnate) to the substrate or sometimes standing upright.

These lobes are adorned with scattered, hair-like extensions (fibrils) that are similar in colour to the thallus and measure 1–1.5 mm long, and there are also a few whitish root-like structures (rhizines) on the lower surface.

[5] The upper cortex of the thallus is fibrous, about 20–50 μm thick, composed of tightly packed 4 μm-thick fungal filaments (hyphae).

[5] Arthonia anjutae is a lichenicolous fungus that has been recorded parasitising Teloschistes spinosus specimens collected in South Australia.