Notes: Niebla josecuervoi was originally described from rock populations at San Quintín, but soil populations occur as well throughout the species' range. As Spjut (1996) noted, "the attachment point of N. josecuervoi may become detached as the thallus increases in size; moreover, the decumbent basal branches hardly seem distinguishable from those of other soil species." The San Quintín area rock populations can often be distinguished from N. homalea (mostly the divaricatic race) because of greater branching and a duller cortex. Soil populations may be recognizable to some degree in the San Quintín area; however, mixed rock or soil populations elsewhere cannot be reliably distinguished. Niebla pulchribarbara was also described from San Quintín based upon soil populations. Marsh and other researchers subsequently found saxicolous populations, so that like nearly all other depsidone and depside chemical races, a reproductive "pair" exists - one a usually sterile soil population reproducing by fragmentation and the other a fertile rock population. Bowler (in ed.) suggests that these clonal and spore producing reproductive pairs likely reflect the higher success of spore reproduction on rock as opposed to soil, where clonal or fragmentary reproduction is successful. The soil populations form dispersal bridges for the chemical representatives of N. josecuervoi and N. homalea. There are local ecotypes in most chemical races of both N. homalea and N. josecuervoi, usually reflecting wind-trimming or other differences in exposure. Spjut (1996), for example, noted a "ridge form" of N. josecuervoi at San Quintín. The dozens of species based upon chemotaxonomic or rock versus soil populations are regarded as synonyms in this treatment. We recognize a single species for the depside (N. homalea) and a second one for the depsidone lineages (N. josecuervoi).
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