Vermilacinia leonis is a fruticose lichen usually found on branches of shrubs in the fog regions along the Pacific Coast of North America and South America; in North America it is found on the southern half of the main peninsula of Baja California north to the southern coast of the Vizcaíno Peninsula.

In South America, it occurs on bushes and rocks in Chile; reported from Colchaqua (Valley) and Santiago [1] The epithet is in regard to absence of the black transverse bands often seen in other species such as V. leopardina, V. tigrina and V. zebrina.

Vermilacinia leonis is classified in the subgenus Cylindricaria in which it is distinguished from related species by a flaccid to subflaccid thallus divided into numerous narrow cylindrical branches that produce soredia, powdery masses of green alga and white fungal cells that form in pincushion-like heads (capitate), also called soralia because of their regular shape.

Two other sorediate species, described in the genus Niebla, one of which is similar to some forms of V. cephalota, was distinguished by dot-like (“punctiform”) soralia that develop on terminal acicular branchlets; another has a flattened thallus similar to Ramalina lacera, but referred to Niebla by the presence of the depside methyl 3,5 dichlorolecanorate;[2] however, it reportedly lacks pycnidia,[2] generally present in all other species of Vermilacinia but not always in all thalli of a species (e.g., V.

[1] The genus Vermilacinia is distinguished from Niebla by the absence of chondroid strands in the medulla,[6] and by the major lichen substance predominantly of terpenes.