Thallus: fruticose, pendant, attached with a holdfast, sparingly branched branches: cylindrical to gently angled, 1.5 to <3 mm wide, 3-4.5(-10) cm long surface: green, yellow-green, or white, smooth or lacunose medulla: white, hyphae "in bundles and in a net-like lattice" (Spjut, 1996)" Apothecia: subterminal to terminal, common, occasionally in clusters disc: gray, gently concave to flat asci: clavate, 8-spored ascospores: hyaline, 1-septate, fusiform, straight to slightly curved, 10-14 x 3-4 µm Pycnidia: black, immersed, on upper 2/3 of branches conidia: narrowly ovoid Spot tests: K+ yellow to orange, P+ yellow to deep red Secondary metabolites: salazinic acid, triterpenes, zeorin, (-)-16α-hydroxykaurane, usnic acid, and T3 triterpene (fide Spjut, 1996). Substrate and ecology: on maritime rocks World and Sonoran distribution: southern California, Baja California Sur (Vizcaíno Peninsula) and Baja California on Cedros Island. Notes: The sparingly branched, long, cylindrical and slender blades of this pale, rock species are characteristic and make Niebla cedrosensis easily distinguishable from other Nieblae on rocks within its narrow range. Its cortex is smooth or lacunose, and is either light green or white. Subterminal or terminal apothecia are common, as are black pycnidia.