Niebla cornea

©The World Botanical Associates Web Page
Prepared by Richard W. Spjut
October 2005, Sep 2012
Additions May 2017, Sep 2021, Dec 2021

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
 
Manuscript presented 2021 on Authorea. April 05, 2021.
DOI: 
10.22541/au.161766187.74749853/v1

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


 

Southwest of San Quintín in the Punta Mazo Reserve (managed by Terra Peninsular), on E side of Bahía Falsa in shoreline boulder outcrops. Leavitt et al. 16-863, Dec 2016

 

Southwest of San Quintín in the Punta Mazo Reserve (managed by Terra Peninsular), on E side of Bahía Falsa in shoreline boulder outcrops. Leavitt et al. 16-847, Dec 2016

Southwest of San Quintín in the Punta Mazo Reserve (managed by Terra Peninsular), on E side of Bahía Falsa in shoreline boulder outcrops. Leavitt et al. 16-857, Dec 2016

Morro Bay, CA, Hale 33688,
July 1965, holotype

San Cruz Island, CA
Bratt 4475

Bahía de San Quintín, BCN,
Spjut 9329D, May 1986 (scanned
from a black & white photocopy of specimen at US)

Los Angeles Co., Palo Verdes, CA
Darrow 314 (COLO)

 

San Clemente Island, CA
Murbarger 151
(COLO)

 

Santa Cruz Island, CA
Schuster 15a
(COLO)

+

Santa Barbara Island, CA
Bratt 3712

San Luis Obispo Co., CA
Riefner 86-25 (COLO, p.p., mixed
with Vermilacinia laeviagata)

     Niebla cornea is a fruticose lichen that occurs mostly in California along the Pacific Coast south of San Francisco, mainland and in the Channel Islands, and in Baja California near San Quintín. It also was also reported further south near Punta Santa Rosalillita along Hwy 1. based on a single specimen found in a sample of N. flagelliforma (divaricatic acid), that hardly differed from that species, except for having sekikaic acid. The species is recognized by the flat but turgid ribbon-like branches—that unlike most other species of Niebla—hardly twist.  This is generally evident by the cortical ridges that define the primary branch margins ± in the same plane. The primary branches frequently dilate and digitately divide near apex into short to long terminal flattened branchlets.  The cortex is ± smooth and glossy, appearing stretched in some thalli to the extent that varicose-like ribs become apparent.  Another distinctive feature of Niebla cornea is the development of cup-like (cupular) apothecia in small aggregates near ends of branchlets, often in 4's. 

     Niebla cornea is most similar to N. eburnea, especially their type specimens, which are from relatively distant locations, near Cerro Solo (BCN) and at Morro Bay (CA).  Niebla eburnea is generally distinguished by the primary branches half-twisted near base and again near apex, by narrower terminal branchlets, by having a paler cream-like cortex (rarely dark green), by the presence of the lichen substance divaricatic acid (as opposed to sekikaic acid in N. cornea), and by the solitary disciform apothecia that form terminally, or develop on short subterminal branchlets.  The epithets for both species were chosen for their distinct but similar cortical features.

     Niebla cornea may be confused with Vermilacinia laevigata, which can be recognized by  the shallow recessed apothecial disk, in contrast to cup-like in N. cornea, the apothecia usually positioned just below the apex near the branch margin often on a short lobe extension. Another similar species, V. johncassadyi, differs by having branches spreading recurved and by apothecia  developing in terminal aggregates, or appearing to abort development below apex along the branch margins. The key identifying features for N. cornea are the presence of medullary chondroid strands and the depside secondary metabolite, sekikaic acid.

       Niebla cornea might also be confused with N. homalea, which differs by the narrower branches with margins that frequently alternate or twist 90 degrees from base to apex, and by the lichen substance of divaricatic acid. 

     Specimens of N. cornea collected by Charis Bratt (3712) from Santa Barbara Island and Riefner (86-25) from Morro Bay differ in the marginal and intermarginal cortical ridges densely covered by pycnidia and/or nodular apothecia.  They are remarkably similar for having been collected from disjunct locations.  They appear related to N. lobulata by the lobulate margins, wavy cortical ridges, and by the irregular presence of fringed branchlets. They also appear related to N. dissecta by the thicker cortex and sinuous cortical  ridges, and to a specimen of a divaricatic-acid species, N. laminaria, collected from Pt. Loma in San Diego Co. (Bratt 5631), which has a thallus divided into short rounded lobes that are also similar to the Riefner specimen (86-25) except for spine-like segments.  

     Niebla dissecta differs from N. cornea by its 3–4 longitudinally ribbed branchlets, and by the thallus spreading more at the base than in height. This is in further contrast to the long sublinear branches of  N. disrupta.  The relationships of N. cornea 'variants' are shown in the following dendrogram in comparison with N. dissecta and its variants.

      DNA analyses employing restriction site-a DNA sequencing (RADSeq) that selected 40 specimens representing 22 species and one variety (sensu Spjut 1996) supported N cornea  for specimens collected in the Channel Islands (Santa Barbara, San  Clemente) and near San Quintín in Baja California (Jorna et al., see Leavitt citation above).   A morphological dendrogram for N. cornea as it relates to N. dissecta, a species endemic to California, type from San Mateo County, is shown below. DNA have not been obtained for N. dissecta.

 

For more discussion and reference materials see Introduction to Niebla