Niebla and Vermilacinia (Ramalinaceae) from California and Baja California.  
Spjut, R.W., 1996. ISSN 0833-1475, 208 pp.  
Sida, Botanical Miscellany: 14. Botanical Research Institute of Texas, Inc.

Evolutionary history of coastal species of fog lichen genera
Niebla, Ramalina and Vermilacinia
Emmanuel Sérusiaux & Richard  Spjut
Baja California, Jan-Feb 2016

Spjut R, Simon A, Guissard M, Magain N, Sérusiaux E. The fruticose genera in the Ramalinaceae (Ascomycota, Lecanoromycetes): their diversity and evolutionary history.  MycoKeys. 2020 Oct 30;74:109-110].
MycoKeys. 2020;73:1-68. Published 2020 Sep 11. doi:10.3897/mycokeys.73.47287

Niebla pulchribarbara

Niebla pulchribarbara

Rocky mesa E of San Antonio del Mar, Spjut & Marin 11182,
Apr 1990

Niebla pulchribarbara x N. palmeri?

Between El Rosario and Punta Baja, Spjut & Sérusiaux 17078, phylogeny in depsidone clade. Specimen collected between El Rosario and Punta Baja, N 30°00.075 W 115°45.965' 140 m.  TLC on separate occasions from the same collection show different results. One found with protocetraric acid, and with triterpenes, the other found hypoprotocetraric acid and also with triterpenes. Image color modified by autotone in Adobe Photoshop to accentuate triterpenes.  Divaricatic acid normally yellow.

     Niebla pulchribarbara has been recognized as a species by its chemotype within the genus by producing only protocetraric acid (without triterpenes).  It has been reported only from two locations: (1) sandy beaches near Bahía de San Quintín and (2) lava rubble on a mesa above San Antonio del Mar.  In the latter location, two thalli have been collected on three separate occasions where they constituted perhaps 5% of the Niebla community of N. arenaria, N. effusa, N. fimbriata, N. josecuervoi, N. juncosa, and N. versiforma.  However, specimens with protocetraric acid have been found with sekikaic acid, or with sekikaic acid and triterpenes.  As shown above, their ITS phylogeny is within the depsodone clade where it groups with other unusual chemotype specimens.  Niebla pulchribarbara here is recognized to contain only protocetraric acid even though not supported by DNA phylogeny.

     Niebla pulchribarbara was originally described by Rundel and Bowler from a vegetation study they conducted at Bahía de San Quintín (Rundel et al. 1972); however, Bowler and Marsh (2004), felt it was no longer worthy of recognition and treated it as a synonym of N. josecuervoi, a species that had also been described by Rundel and Bowler in the same study (Rundel et al. 1972).  The authors of N. pulchribarbara did not indicate its relative abundance as they did for other species, apparently because they distinguished N. pulchribarbara from N. josescuervoi by the terricolous habit (Rundel 1978) rather than by secondary lichen substances as was later done by Spjut (1996). Moreover, N. josecuervoi is recognized without a well defined attachment point as shown for specimens collected on Punta Canoas (e.g., Spjut 11297)

     The morphological features of Niebla pulchribarbara appear intermediate between N. josecuervoi and N. effusa as evident by the development and shape of branchlets.  Niebla pulchribarbara differs slightly from these related species in the longer branchlets, but relatively few specimens are known so it is difficult to draw any taxonomic conclusions on this one feature. The thallus lacking any clear dominant branch and the relatively rigid branches with raised longitudinal cortical ridges are features shared with N. effusa.  The appearance of long secondary branchlets, often close together along the upper side of a primary branch, is also similar to N. josecuervoi.  In view of the limited material for study, it seems best to identify N. pulchribarbara by the lichen substance, protocetraric acid.

     Spjut & Sérusiaux discovered other specimens with protocetraric acid. These appear to be hybrids by the additional lichen substances of triterpenes and other depsidones.  However, these anomalous thalli cluster in a phylogeny from different locations; thus, they may actually represent a distinct species complex.

Additional references cited:

Bowler, P. A. and J. Marsh.  2004. Niebla.  Lichen Flora of the Greater Sonoran Desert 2: 368–380. 

Rundel, P.W. 1978. Ecological relationships of desert fog zone lichens.  The Bryologist 81: 277–293.

Rundel, P.W.,  P.A. Bowler & T.W. Mulroy. 1972. A fog-induced lichen community in northwestern Baja California, with two new species of Desmazieria. The Bryologist 75: 501–508.