Niebla disrupta

©The World Botanical Associates Web Page
Prepared by Richard W. Spjut
October 2005, Sep 2012, Sep 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.

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


 

Marin Co., Pt. Reyes, CA,
L. E. Rose,
16 Jul 1952
TLC: Sekikaic acid & triterpenes, 3 Sep 1993

Marin Co., Pt. Reyes, CA
V. Ahmadjian, 20 May 1966
TLC: Sekikaic acid & triterpenes, 1 Sep 1993

Tomales Bay, near Marshall, CA
Cooke & Cooke, 16 Jul 1942
TLC: Sekikaic acid & triterpenes, 3 Sep 1993

Pt. San Pedro, San Mateo Co., CA
Herre & Doty 3332, 22 May 1942
(L75743, L74403, COLO)

 

Marin Co., Willow Camp, CA
H. E. Parks 2733,
25 Apr 1925
TLC: Sekikaic acid & triterpenes, 3 Sep 1993

 

Niebla disrupta, Lectotype
 

 

Niebla disrupta
Santa Barbara Island
Bratt 5182
, Jan 1987.
 

 

     Niebla disrupta is a fruticose lichen that has been recognized to occur largely in coastal areas of California. The geographical range of N. disrupta partially overlaps with N. homalea in the Channel Islands and on Isla Guadalupe in Baja California and on the mainland from San Luis Obispo to Mendocino Cos. It is notably absent south of Morro Bay. The type locality is not specifically known; however, the type specimen compares most closely to specimens from coastal Marin County, while the collector and collection date are also unknown. The type would appear to be a fragment of a specimen from perhaps the Museum of Natural History in Paris

     Niebla disrupta is morphologically similar to N. homalea from which it is distinguished by having sekikaic acid and not divaricatic acid.  Despite their similar morphology, chemistry, and geographical distribution, they are not sibling species.  DNA phylogeny studies by Spjut et al. (2020) and Jorna et al. (Authorea. Apr 2021) reveal that species of Niebla producing sekikaic acid form a separate clade; however, sekikaic acid specimens have not been reportedly collected in California for the DNA studies.

     Niebla disrupta may be recognized morphologically by the terminal whip-like, often sharply pointed branchlets, usually with undeveloped apothecia, while mature apothecia are develop more near base of thallus.  The whip-like branches often change direction where apothecia initiate. Niebla homalea, in contrast, has mostly ribbon like branches with apothecia maturing nearer apex, usually on a short broad lobe shaped much like the branch itself.  Both species may occur together as evident from herbarium collections.

     Variants assigned to this species include specimens collected by Charis Bratt 5182 from Santa Barbara Island and by Reifner 86-25 (Fig. 8.4 in Spjut 1996) from Morro Bay, and possibly a Stephen Sharnoff  photo titled “Niebla homalea 4” reportedly taken on Santa Rosa Island. These 'disruptoid' nieblas, which share the terminal whip like branches with subterminal apothecia, are similar to N. suffnessii that differs by the more rounded branches in x-section with a thinner cortex; however, they appear to belong to a separate undescribed southern California species complex that includes variants of N. cornea, N. dissecta, N. laminaria, and possibly N. lobulata; the latter has not been recognized from California.

     The two Niebla disrupta variant specimens mentioned above have an irregular network of cortical ridges between branch margins; the branches appearing 3–4 angled in cross section as seen in N. dissecta, a species recognized by a broader than tall thallus and terminal wide-spreading branchlets arising from dilated branches. The apothecia are larger and positioned more on the face of the branch rather than perpendicular to an expanded margin of the branch.  They are referred to N. disrupta by the thallus appearing taller than wide, and by the terminal whip-like branches as just noted.  This variation may be a product of geographical (evolutionary) differentiation of N. disrupta south of Monterrey Co. that involved  genetic exchange with variants of N. cornea occurring further south and on Santa Barbara Island, N. laminaria at Pt. Loma, and N. aff. lobulata in the Santa Monica Mts.

     A related sekikaic acid species, Niebla fimbriata, has spindle-shaped branchlets that are relatively straight in a wind-swept appearance along one or both margins of an aching branch, analogous to “scorpiod cyme (seund) type of inflorescence in angiosperms.

      The sekikaic-acid species considered most similar to N. disrupta are Niebla cornea and N. dissecta. They are distinguished in the following table, diagnostic characters in bold type.

 Character

N. disrupta

N. cornea

N. dissecta

 

 

 

 

Branching general

Anisotomic.

Anisotomic.

Anisotomic.

Terminal bifurcate
branches

Usually not evident.

Bifurcate and rabbit-like ear-lobes, or trifurcate with unequal lobes, or often expanded with digitate-like segments

Common, antler-like, often 3-pointer in one division, 2-pointer on other, more flattened and digitate in type

Branch shape lengthwise

Sublinear.

Scoop-like to ribbon-like

Sublinear with expanded lobes, especially near apex.

Branch shape cross-section

Elliptic or 3–4 angled in one variant

Elliptic.

Prismatic, or ±4-angled.

Branches twist

Frequent between base and apex.

Irregularly twisted or not twisted, often irregularly contorted.

Frequent between base and apex.

Branch margin

Usually well-defined,  acute.

Rounded to acute, sometimes thickened.

Variable.

Cortex

Glassy, transversely cracked at various intervals.

Mostly smooth, irregularly transversely cracked or reticulate ridged

Dull, transversely cracked and reticulate ribbed with tertiary longitudinal sinuous ridges between the margins.

Apothecia

Subterminal undeveloped apothecia on long whip-like branches, mature apothecia often on lower short lateral branches, oriented perpendicular to branch margins, shorter branches often at nearly right angles.

Terminal in small loose aggregates, often in 4's on short lobes of an  expanded branch, or sessile and in plane with the main branch.

Generally most developed near base of thallus, sessile, submarginal.