Niebla laminaria is recognized by having divaricatic acid and by the presence of fimbriate to nodular branchlets, or lobes, along a primary branch.  It is mainly a California species that is distinguished from relatives in the coastal desert of Baja California by the relatively thick cortex and solid medulla; however, it is also recognized to occur in the Northern Vizcaíno Desert.  The type was pulled out of a ~100 g sample of N. homalea collected for antitumor and anti-HIV screening in the coastal chaparral region of Baja California Norte near Punta Banda.  Niebla homalea was distinguished by having relatively smooth branch margins.  Additional specimens of N. laminaria from other locations, which reinforce the taxonomic features, appear relatively rare, and because none fit well within the circumscribed Californian species such as N. testudinaria, N. eburnea and N. homalea, they seem best classified under a distinct species.  Also, the taxonomy of the Baja California species considers differences in branch marginal features; thus, recognizing N. laminaria by its irregular marginal features, compared to relatively smooth margins in N. homalea and N. testudinaria, provides clarity to all species in question.  Niebla laminaria can be further characterized by having relatively few branches from a holdfast.  An occasional morph of N. undulata (Spjut 1996, Plate 9E) resembles the type of N. laminaria in the blade-like branches; however, it differs by the bluish-green, thinner cortex and by a fistulose to subfistuose medulla in which these features seem more related to the contorted appearance of its thallus branches.