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

Evolution and diversification of Niebla
Steven 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.

Southwest of San Quintín in the Punta Mazo Reserve on volcanic slopes of Volcan Sudoeste
Leavitt et al. 16-703, Dec 2016

North of El Rosario along the Transpeninsular Hwy 1, small ridgeline west of highway dominated by euphorbs and small rocks.  Leavitt et al. 16-829, Dec 2016

Along Punta San Telmo road on cacti-dominated hillside.  Leavitt et al. 16-1166, Dec 2016

N of Punta San Rosallilita, Canyon de San Andrés, Spjut & Sérusiaux 17114, Jan 2016.

Just S of Tijuana near Rosarito, Spjut & Marin 9027T.  Thallus immature
May 1985.

Isla San Martín, BCN
Moran 1055 (COLO)

San Luis Obispo Co., CA. Bratt 3212

La Misíón, between Tijuana and Ensenada.
Weber & Santesson
(COLO: 43035)

Santa Cruz Is., CA
Bratt 6431

Santa Barbara  Co.,
Santa Ynez Mts.
Bratt 7202

San Mateo Co. CA
Howe 92 (COLO:13353)

Monterrey, CA
Herre 256

Santa Cruz Island
Bratt 6427

Lectotype: Menzies,  Monterrey, CA (H-NYL 37213, H)

Pt Lobos State Park
Monterrey Co., CA
CalPhotos: Ron Wolf

     Niebla testudinaria is a fruticose lichen found on rocks along the Pacific coast from Marin County, California  to near Punta Santa Rosalillita in Baja California, and also in the Channel Islands south into Mexico on Isla San Martín (just off the coast of San Quintín), and west to Isla Guadalupe.  It appears to have been most common on the Monterrey Peninsula such as in Point Lobos State Park, where also occurring with Niebla eburnea,  Vermilacinia procera and V. laevigata. During the mid to late 1980's, it was observed to be locally common just south of Tijuana near Rosarito on talus-like rubble in association with Vermilacinia combeoides and V. pumila. This area has since undergone extensive real estate development. 

     Niebla testudinaria is recognized by the primary branches spreading outwards from their base, in contrast to the upright habit of the fastigiate branches that characterizes Niebla homalea, and by reticulate cortical ridges on the face of the branches in contrast to the relatively smooth surface of Niebla eburnea.    

     The epithet, testudinaria, provided by Nylander, suggests that the species was recognized for the reticulate pattern on the cortical surface, like that seen on tortoise shells, especially thalli with dilated branch segments. The varicose vein-like ribbing within a relatively thick cortex (>75 µm), along with the presence of divaricatic acid, also distinguishes N. testudinaria from related species; Niebla homalea, for example, has relatively narrow linear branches with a glossier cortex transversely cracked at various intervals.  Another characteristic feature of N. testudinaria is that branches terminally divide ± equally, dichotomous or digitately, especially those that appear arcuate and compressed where they divide. This is in contrast to unequal divisions of the primary linear subterete branches of N. homalea.

     The reticulate ridging that characterizes Niebla testudinaria is seen in thalli with narrow to irregularly widened branches. The narrower parts appear prismatic in cross-section, the wider parts often expand and flattened like the palm of a hand from which ± isodichtomous or isotrichotomous (isotomic) branchlets arise.   Relatively short thalli, wider than tall (e.g., Moran 1055 from Isla San Martín, Leavitt et al. 16-1166) resemble N. caespitosa, which differs by its relatively thinner cortex as evident by more sharply defined cortical ridges, and by irregularly lacerated branches. Charis Bratt 2303 from Santa Cruz Island (N. caespitosa), which might be referred to N. testudinaria, was distinguished by its thinner cortex; otherwise, it is similar to Spjut & Sérusiaux 17114, and Leavitt et al.  16-829, 16-703 shown above.  Charis Bratt 6431 from Santa Cruz Island and Charis Bratt 7202 from the Santa Ynez Mountains shown above closely resemble Niebla halei by their linear shaped prismatic branches; N. halei, described  from San Bruno Mountain, differs by its much smaller thallus.  These Charis Bratt specimens may prove to be a distinct species, or perhaps could be referred to N. halei in further study.

     DNA phylogeny of N. testudinaria, as with most other depside species, reveals it to occur in different subclades, or microclades; however, statistical analyses (BPP, Stacey) for three specimens indicated only one species. Specimens collected by Leavitt et al. were not included in Jorna et al. (2021).

     The character feature of reticulate cortical ribbing of Niebla testudinaria appears plesiomorphic to various subtaxa that might be formally named. This is exemplified in the following dendrogram.

           References:

Bowler, P. A, R. E. Riefner, Jr., P. W. Rundel, J. Marsh & T.H. Nash, III. 1994. New species of Niebla (Ramalinaceae) from western North America. Phytologia 77: 23-37.

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

O’Brien, H. E., J. Miadlikowska, and F. Lutzoni 2009. Assessing reproductive isolation in highly diverse communities of the lichen-forming fungal genus Peltigera. Evolution 63-8: 2076–2086.

Culberson, C. F., W. L. Culberson & A. Johnson. 1988.  Gene flow in lichens. American Journal of Botany 75: 1135–1139.

DePriest, P. T. 1994. Variation in the Cladonia chlorophaea Complex II: Ribosomal DNA variation in a Southern Appalachian population. The Bryologist 97: 117–126.

Lohtander, K., L. Myllys, R. Sundin, M. Kllersj, and A. Tehler. 1998. The species pair concept in the lichen Dendrographa leucophaea (Arthoniales): Analyses based on ITS Sequences. Bryologist 101: 404–411.

Montagne, D.M.  1852. Diagnoses phycologicae. Ann. Sci. Nat. Sr. 3, 18, 302-319.

Spjut, R. W. 1995. Vermilacinia (Ramalinaceae, Lecanorales), a new genus of lichens. Pp. 337-351 in Flechten Follmann; Contr. Lichen. in honor of Gerhard Follmann, F. J. A. Daniels, M. Schulz & J. Peine, eds., Koeltz Scientific Books, Koenigstein.

_________. 1996. Niebla and Vermilacinia (Ramalinaceae) from California and Baja California. Sida, Botanical Miscellany 14: 1–207, 11 plates.

Additional References: See Niebla.