The lobes of the thallus are contiguous to slightly overlapping, flat, and range from 0.5 to 2.0 mm wide, often showing more or less dichotomous branching.

The upper surface is yellow-green, turning darker with age, and is shiny at the tips but becomes rugulose (wrinkled) and cracked over time.

[2] Reproductive structures include sessile to slightly stalked apothecia (fruiting bodies) that are 1–3 mm wide with a dark brown to black disc.

[2] Chemical spot tests on the lichen show no reaction to potassium hydroxide (K−) on the cortex, but it is K+ (yellow to dark red) in the medulla, and is P+ (orange-red).

[2] Xanthoparmelia nanoides has been found exclusively at its type locality on granite rocks in a heathy, dry sclerophyll forest within the Monadnocks Nature Reserve near Albany, Western Australia.