[1] In 2017, Divakar and colleagues used a recently developed "temporal phylogenetic" approach to identify temporal bands for specific taxonomic ranks in the family Parmeliaceae, suggesting that groups of species that diverged within the time window of 29.45–32.55 million years ago represent genera.

These lichens can appear either leaf-like (foliose) or shrubby (fruticose) in growth form, typically reaching up to 1.5 cm in height.

The main body (thallus) of Kaernefeltia ranges in colour from pale olive-brown to greenish-black, often appearing paler in the centre.

The branches or lobes can be either smooth or covered with small bumps and ridges, and sometimes have a whitish, powdery coating (pruina).

The sexual reproductive structures (apothecia) are commonly found on these lichens, appearing as dark brown or blackish discs that can be located along the edges or surface of the thallus.