[2] Flourishing in coastal environments, Roccella gracilia predominantly grows along the coasts of Baja California and the Galápagos Islands, preferring the trunks, branches, and twigs of trees, but it is also found on rocks and cliffs.

[3] Soredia, which are granular clusters of fungal and algal cells for asexual reproduction, are commonly found in Roccella gracilia but do not coexist with ascomata (spore-producing structures).

These soredia turn C+ (red) and are located in maculiform (i.e., marked with spots) soralia, forming small patches that often merge to cover a significant portion of the lobe surface.

In these coastal regions, it thrives on a variety of suitable substrates, showing a preference for growing on the trunks, branches, and twigs of different trees and shrubs.

[3] The world distribution of Roccella gracilia is quite extensive along the coasts, stretching from north of the San Francisco area in California down to Arequipa, which is south of Lima, Peru.