[2] Though previously believed to lump together several lineages such as Letharia gracilis and others, there now exists more specific characteristics to identify the species.

[5] Another article found them to be "ranging from the southern portion of British Columbia south to California and southwest through northern Idaho and western Montana".

[7] Letharia, a fruticose genus of lichenized Ascomycetes, was historically believed to include only L. vulpina and L. columbiana.

The intricate and divaricate ramified thallus produces these irregular branches, 0.5–3 mm wide, with uneven thickness, and a bright yellow-green color.

[2]  In the midst of these spiky branches are the “brown eyes”, or the fruiting bodies, whose function it is to make spores for reproduction.

A common characteristic of Letharia is the presence of vulpinic acid, a secondary metabolite of the symbiosis between fungi and algae.

[8] Some other Natives Americans used the lichen in medicine, balms, or as a source of dyeing water with its recognizable bright-yellow color.