Domain: Eukarya
Kingdom: Fungi
Phylum: Ascomycota
Class: Lecanoromycetes
Order: Lecanorales
Family: Parmeliaceae
Genus: Letharia

Common Name: Common Wolf Lichen

Bright yellow shrubby fruticose lichen on conifers in montane forests. Looks like a yellow moss from a distance, often covering the entire northern side of a tree.

THALLUS: bright yellow to greenish yellow, irregularly angled branches
SOREDIA: abundant, often appearing isidioid but cortex clearly eroded
APOTHECIA: rare, deep brown cups
PYCNIDIA: rare, black
CHEMISTRY: K- (vulpinic acid)

Western North America and western Eurasia.

Open conifer forests in mountains. On both bark and wood, often growing high up.

The only thing that looks anything like it is L. columbianum, with which it often grows. See the discussion under that species for differences between these two species and other yellow genera.

(See also the discussion under L. lupina, a virtually identical species described circa 2011 by Susi Alterman and Trevor Goward.)