Niebla arenaria

Although Niebla arenaria was described in 1996, it had been known earlier as a chemical variant of Niebla pulchribarbara that was distinguished from Niebla homalea by containing depsidones instead of depsides, and from Niebla josecuervoi by the lack of central basal attachment point and without apothecia. These two groups of lichen substances could be separated by the medulla reaction to para-phenylenediamine, depsidones (pd+), depsides (pd-). It was stated that: "This beautiful terricolous species forms extensive discontinuous mats...on beach terrace deposits atop coastal bluffs south of El Rosario and beyond, often in densities great enough to color the landscape yellow-green." The extensive terricolous lichen growth has since been recognized to comprise N. arenaria and Niebla effusa, with occasional Niebla juncosa. Niebla pulchribarbara is recognized strictly by the lichen substance protocetraric acid, and is considered a rare species found only in northern Baja California; however, one of the coauthors who first described N. pulchribarbara, has since considered the species to be a morphological and chemical variant of another species he described, N. josecuervoi, along with N. arenaria, and all other species that contain salazinic acid and hypoprotocetraric acid.