Vermilacinia vesiculosa is a fruticose lichen known only from a vertical rock face north of Punta Canoas along the Pacific Coast of Baja California.

Lichen substances are of the chemotype found in most species of the subgenus: an unknown T3, the triterpene zeorin and the diterpene (-)-16 α-hydroxykaurane, with accessory β-orcinol depsidone, salazinic acid.

The thallus was pendulous, lying flat against the vertical rock face, and has a cortex 100–200 μm thick.

[1] Vermilacinia vesiculosa was discovered by Richard Spjut, assisted by Richard Marin, while climbing a vertical rock face along the north side of Punta Camachos, which lies between Puerto Catarina and Punta Canoas.

The species was growing in a sheltered spot below a rock overhang, 320 meters above the sea, 15 March 1994.