Thallus: fruticose, subpendulous in large plants, sparingly branched branches: cylindrical to subcylindrical, often blackened on one side, usually blackened about the base, solid and stiff, cracking when bent, 1-2-(-4) mm in diam., up to 8 cm in length, with occasional lateral branchlets and pointed branch apices surface: greenish yellow, rigid, with black maculae medulla: white, lacking well defined hyphal aggregations Apothecia: common, terminal or subterminal, single or in clusters, up to 6 mm in diam. disc: white to tan, concave to convex, often lobed asci: clavate, 8-spored ascospores: hyaline, 1-septate, ellipsoid, straight, 11-12.5(-13) x 3.5-4 µm Pycnidia: black, immersed, not as abundant as in many other Nieblae conidia: straight, rod-shaped, c. 4 x 1.5 µm Spot tests: negative, except when K+, P+ for salazinic acid Secondary metabolites: (-)-16α-hydroxykaurane, +zeorin, +salazinic acid, terpenes, fatty acids, +usnic acid, and T3 triterpene fide Spjut (1996). Substrate and ecology: rocks and cliffs along the immediate coast at sites within the sea breeze and fog zone World and Sonoran distribution: endemic to the west coast of central California south to the Vizcaíno Region in Baja California, including Cedros Island. Notes: Niebla procera is a rock inhabiting species occurring on ocean-facing coastal cliffs, boulders, and lava flows with an immediate fog and ocean breeze zone of influence. The greenish yellow branches are cylindrical to subcylindrical, usually less than 2 mm wide and 3 (-8) cm in length. The cortex is generally smooth, and the branches break when bent. The surface has black spots and often large areas are blackened. Apothecia are common, on the terminal areas of a branch, either in clusters or solitary. At various sites in California, thalli become the largest (up to 8 cm), while at southern localities, like the sand spit at San Quintín where it is the most common, it only reaches half that length or less, but occurs in dense, blanketing stands. Its branches are thinner and its thallus is larger than those of N. robusta. Black-chambered pycnidia are laminal and subterminal, but not as abundant, as in many other Nieblae. White, cottony exudates are present in most herbarium specimens.