The increased branching of the thallus towards apex is similar to that of Niebla dactylifera, known only from San Nicolas Island; it differs in having the lichen substance, sekikaic acid. The cortical ridging and branching of N. halei are also similar to specimens collected by Charis Bratt on Santa Cruz Island (Bratt 6431) and in the Santa Ynez Mountains on mainland California (Bratt 7202), referred to Niebla testudinaria by the larger size and less frequent occurrence of short bifurcate branches near apex.