Niebla and Vermilacinia (Ramalinaceae) from California and Baja California.  
Spjut, R.W., 1996. ISSN 0833-1475, 208 pp.  
Sida, Botanica 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

Evolution and diversification of Niebla
Steve Leavitt et al., Baja California, Dec 2016

 Jorna J, J Linde, P Searle, A Jackson, M-E Nielsen, M Nate, N Saxton, F Grewe, M de los Angeles Herrera-Campos, R Spjut, H Wu, B Ho, S Leavitt, T Lumbsch.  Species boundaries in the messy middle -- testing the hypothesis of micro-endemism in a recently diverged lineage of coastal fog desert lichen fungi. Ecology and Evolution. Published Online: 20 Dec 2021.  https://onlinelibrary.wiley.com/doi/full/10.1002/ece3.8467

See also  Introduction to Niebla and its phylogeography

Niebla spatulala hybrid complex. W of Bahía de Tortugas, towards Punta Eugenia, N 27°49.701 W 115°03.454 35-40 m, Spjut & Sérusiaux 17179a, chemistry variable, acid deficient, or divaricatic acid with salazinic acid. Occurring with N. contorta (divaricatic acid), 17179b.

Niebla spatulala hybrid complex, partial vegetative hybridization by fusion of two different thalli evident. 17179 previously included under N. homaleoides (left thallus) by the absence of triterpenes and depsidones  (acid deficient). Right thallus with divaricatic acid and salazinic acid (N. contorta x  N. spatulata).
W of Bahia de Tortugas, towards Punta Eugenia, N 27°49.701 W 115°03.454 35-40 m. Spjut & Sérusiaux 17179a2, Jan 2016 

7 mi S of Rosarito along Hwy 1, Spjut 10511, Apr 1989, hypoprotocetraric acid, northernmost occurrence of the Southern Vizcaíno Desert, north of Guerrero Negro

Isla Cedros, Spjut & Marin 10546 (salazinic acid) & 10547 (hypoprotocetraric acid), Apr 1989 ,

Sierra Hornitos,
Vizcaíno Peninsula,
Spjut 9704, May 1986, salazinic acid

Niebla spatulata complex
draft of ITS phylogeny in part, generated by Professor Sérusiaux, color and identifications added by Spjut et al. 2020 for further study in regard to publication cited above.

Map showing collection sites

     Niebla spatulata is a species of fruticose lichen found largely in Baja California Sur, reaching its northernmost occurrence just north of the state line (near El Tomatal).  It is also  recognized here as a species complex occurring at three major locations: (1-type) Sierra Hornitos on the Vizcaíno Peninsula, (2) Isla Cedros, and (3) near El Tomatal, while found at minor locations in between.  The location, just north of state line of Baja California, was near a border checkpoint, where over the years the Niebla population may have been extirpated.

     The species complex is characterized by a thallus divided into small tufts of flattened branches that are dilated, lacerated and fringed near apex, and by having hypoprotocetraric acid with or without  4-O-demethylnotatic acid and/or salazinic acid (N. flabellata Spjut 1996), rarely with no detectable lichen substances (acid deficient, N. aff. homaleoides).  Niebla spatulata was recognized by Spjut (1996) to occur with  N. flabellata and easily distinguished by lichen substances; however, this distinction has yet to find support in DNA phylogeny, or by analytical species discrimination methods (Spjut et al., 2020). Nevertheless, the close association of N. spatulata thalli exhibiting the same chemo-syndrome  as a monophyletic group distributed over a broad geographical range within a well-defined ecogeographic region  warrants recognition as a species complex. The N. spatulata species complex is also recognized by pycnidia appearing in greater density and slightly larger, and more sharply defined compared to those of N. flabellata, and hypoprotocetraric acid within a population.

     Three cryptic species are evident in the Niebla phylogeny based on both salazinic acid and hypoprotocetraric acid thalli while only one was found by application of BPP and Stacey species discrimination methods based on the N. spatulata described to have  hypoprotocetraric acid  (Spjut et al. 2020, Suppl. 5).   A portion of a ITS-phylogeny presented above shows 17183A and 17183B, identified N. flabellata based on Spjut (1996), that were collected within centimeters of each other, occur in different clades (#9, #10).

     The various chemotypes, which often occur together, are not morphological distinguishable except perhaps for the acid deficient thalli that were identified in the field (for Spjut et al. 2020) by the cortex appearing to have stretch marks.  They were collected on the Vizcaíno Peninsula, while the species also occurs on the southern part of Isla Cedros (Spjut 1996)   Acid deficient thalli had been known only from Baja California Sur. Typical N. homaleoides (acid deficient), is characterized by ± linear branches with a polished cortex, occurring on ridges south of Punta Negra in Baja California. A thallus collected similar to N. spatulata was found at Arroyo Sauces, between Punta Canoas and Punta Blanco, W of Rancho San José. 

Related references:

Fischer, M and N. Louise Glass. 2018. Communicate and Fuse: How Filamentous Fungi Establish and Maintain an Interconnected Mycelial Network. Frontiers in Microbiology. https://doi.org/10.3389/fmicb.2019.00619.

Glass, N Louise, DJ Jacabson, KY Shiu. 2000. The Genetics of Hyphal Fusion and Vegetative Incompatibility in Filamentous Ascomycetes fungi. http://www.plantpath.cornell.edu/Courses/PP602/pdf/annurev.genet.glass.pdf.