[1] Another similar species, Niebla sorediata, which has a relatively thin cortex, 30–40 μm thick, differs by the granular appearance of the isidia that become sorediate (soredium).

homalea f. isidiosa by Henry Willey on the specimen collected by Palmer—that it represented a "contingent phase of R.

"[3] The epithet was adopted by Richard Spjut who also designated the Palmer specimen as holotype (biology) for a new species in his revision of the genus Niebla.

[1] Another isidiate species, Niebla isidiaescens, described by Peter Bowler and collaborators in 1994,[4] based on a type specimen from the southern state of Baja California, differs by the flagelliform (flagellum)branches with a cortex 45–75 μm thick, generally becoming thinner towards apex as in N.

[1] This had been recognized for some time by Spjut under an unpublished name for specimens he collected in southern Baja California that he deposited with annotations at the United States National Herbarium (Smithsonian Institution) in 1986.