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. 2020. The fruticose genera in the Ramalinaceae (Ascomycota, Lecanoromycetes): their diversity and evolutionary history.  MycoKeys. 73: 1–68, published online.
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.

Additional Discussion: See: Introduction to Niebla and its phylogeography

 N of Punta San Rosalillita, Canyon de San Andrés, N 28°42.624, W 114°16.193, 1 m.
Spjut & Sérusiaux 17114. 26 Jan 2016. DNA 4739

N. caespitosa, intermediate to N. dilatata.~ 2 km E of Punta Santa Rosalillita, south side of road; 28°40.572, 114°13.736, 35 m.  Spjut & Sérusiaux 17313. Feb 2016. Cited in MycoKeys 73: 18, Fig. 7 (2020).  DNA 4880.

Vicinity of Punta Catarina, south of point, on gypsum-based badlands.
Leavitt et al. 16-1035, Dec 2016
 

N of Punta San Rosalillita, Canyon de San Andrés, N 28°42.624, W 114°16.193, 1 m.
Spjut & Sérusiaux 17124. Jan 2016. DNA 4746

N of Punta San Rosalillita, Canyon de San Andrés, N 28°42.624, W 114°16.193, 1 m.
Spjut & Sérusiaux 17110. 26 Jan 2016. DNA 4750

~ 2 km E of Punta Santa Rosalillita, south side of road; 28°40.572, 114°13.736, 35 m.  Spjut & Sérusiaux 17305. Feb 2016. Cited in MycoKeys 73: 18, Fig. 7 (2020).  DNA 4878.

N of Punta San Rosalillita, Canyon de San Andrés, N 28°42.624, W 114°16.193, 1 m. Spjut & Sérusiaux 17127. Jan 2016. Cited in MycoKeys 73: 18, Fig. 7 (2020).  DNA 4748.

Vizcaíno Peninsula, road
 to Punta Eugenia, 
Spjut & Marin 10560
Apr 1989

Bahía de Santa María
Spjut & Marin 11377
Apr 1990

 W of Rancho San Andrés
~100 km N of Guerrero Negro, Spjut & Marin 9073
May 1985

W of Rancho San Andrés
~100 km N of Guerrero Negro, Spjut 9887A
May 1986

N. caespitosa x N. podetiaforma?
~100 km N of Guerrero Negro
 between Punta Prieta
and Punta Rocosa,on ridge, Spjut 9971, May 1986

Punta Canoas, lower steps
of mesa near the ocean, on
red pumice, Spjut 11230,
Apr 1990

N. caespitosa x N. marinii? Punta Canoas, lower steps
of mesa near the ocean, on
red pumice, Spjut 11231,
Apr 1990

Ridge N of Punta Rocosa, BCN
Spjut 10300, Mar 1988

Mesa W of Pico Santa Monica, Rancho San Francisco
de la Sierra, 325 m elev.
 Spjut & Marin 10921 Apr 1989

Santa Cruz Island
Bratt 2303

San Clemente Island
Santesson 18043, isotype (COLO)

Geographical Distribution

     Niebla caespitosa is a fruticose lichen widely distributed along the Pacific Coast from the southern California Channel Islands south along the peninsula of Baja California to the Vizcaíno Peninsula (BCS). It is identified by the lichen substance of divaricatic acid (with triterpenes), and by the thallus divided into small tufts of flattened contorted branches.  Near the thallus base the branches are usually short and  relatively narrow-tubular; above they widened and ± digitately divide into shorter irregularly shaped branchlets. The dilated parts of branches generally appear fringed and contorted due to a relatively thin cortex, in comparison to N. testudinaria which differs by the stiffly erect branches that often shortly bifurcate near apex. The relatively thin thallus margins of N. caespitosa appear somewhat jagged or toothed, and lined with pycnidia that develop extensively also along the reticulated ridges of the thallus surface.

     Niebla caespitosa is most common in the southern part of the northern Baja peninsula along the coastal mountains between Punta Rocosa and Punta Rosarito, and along the eastern Vizcaíno Peninsula along the edge of the mesa where it  occurring with Vermilacinia cedrosensis.  On the southern part of the BCN peninsula near Rancho San Andrés, N. caespitosa often occurs with N. flabellata (salazinic acid) and N. flagelliforma (divaricatic acid).

    Niebla caespitosa is similar to Niebla dilatata (divaricatic acid), the latter distinguished by terminal lobes appearing more round than jagged, and thickened in the development of pycnidia.  Niebla flabellata  (salazinic acid) and N. spatulata (salazinic acid, hypoprotocetraric acid) have similarly flattened lacerated branches; they are best distinguished from N. caespitosa (divaricatic acid) by their lichen substances.

     Niebla caespitosa appears to intergrade with N. flagelliforma (divaricatic acid)  at Canyon de San Andrés, between Punta Santa Rosalillita and Punta Negra. This is based on a sample collected there in 1985 in association with N. flabellata (salazinic acid). The type locality for N. flagelliforma is a ridge above the canyon further north perhaps by several km, whereas the type for N. caespitosa is from the Channel Islands, San Clemente Is.    

     Phylogeny of the N. caespitosa is unresolved. Spjut et al. (2020, Fig. 7) show it to be closely associated  with N. flagelliforma collected near Puerto San Andrés where they occur together, and morphologically the upper branches ± arise from a dilated region dividing digitately into three branchlets that slightly curve down near apex as seen in N. flagelliforma.  Specimens collected ~ 2 km south near  Punta Santa Rosalillita were in a separate clade, closely associated with N. podetiaforma. These two species appear to hybridize as identified for a specimen collected 1986.  Additionally, N. flagelliforma appears more variable in the phylogenetic tree as seen by occurring in two other groups, one as sister to N. juncosa var. spinulifera, the other, referred to N. aff. flagelliforma, within a sekikaic acid clade, the specimen reported to have both sekikaic acid and divaricatic acid.    

For more discussion and reference materials see Introduction to Niebla