Niebla | |
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Niebla homalea | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Ascomycota |
Class: | Lecanoromycetes |
Order: | Lecanorales |
Family: | Ramalinaceae |
Genus: | Niebla Rundel & Bowler (1978) |
Type species | |
Niebla homalea (Ach.) Rundel & Bowler (1978) |
Niebla, also known as the sea-fog lichens, is a genus of yellow-green fruticose lichens that grow on rocks, trees, and shrubs within the fog zone of coastal North America, [1] or more narrowly defined to occur on rocks and soil along the Pacific Coast from Mendocino County in California south to Baja California Sur. [2]
The genus name is a substitute name [3] for Desmazieria, a homonym created by Camille Montagne in 1852 who recognized only one species in the genus (D. homalea); [4] however, the name Desmazeria , although not spelled exactly the same but nevertheless considered to be the same (homonym), [3] had been given to a genus of grass (Poaceae) by Barthélemy Dumortier in 1822. The earliest name is the one that must be retained unless the later name is conserved, according to the International Code of Botanical Nomenclature. Additionally, the type species name for Niebla is Niebla homalea, based on the name given to the one species that had been recognized by Montagne for the genus, [5] not Niebla ceruchis. [6]
The genus Niebla has also been interpreted broadly to include the genus Vermilacinia , [7] although both classifications distinguish species by the presence or absence of chondroid strands. In the broad classification, only three species of Niebla with chondroid strands are recognized under two arbitrary groups of lichen substances based on their reaction to chemical spot tests [7] of which the most useful in Niebla appears to be para-phenylenediamine (pd); the nine species in the narrow classification [2] that contain depsidones (pd+) are all placed under N. josecuervoi in the broad classification. [7] A second group that contains depsides but also includes the acid-deficient chemotype (N. homaleoides), collectively treats 32 species under the name N. homalea. The inclusion of the acid-deficient species in N. homalea disregards the chemotaxonomic attribute of a pigment associated with species that contain salazinic acid. [2] Both classifications recognize N. isidiaescens. Eleven other species that are treated in Vermilacinia [2] are distinguished by thallus morphology.
Molecular studies on the North American species of Niebla and Vermilacinia have been limited and contradictory. An unpublished study mentioned in a 1995 communication indicated that Niebla was paraphyletic and that by recognizing Vermilacinia rendered Niebla monophyletic. [8] A later study—that reported largely on Old World species of Ramalina and which included collections of Niebla and Vermilacinia species—concluded that Niebla was monophyletic. [6] However, source material (voucher specimens) cited in the later study for the basis of the DNA analysis of Niebla was reported to be from California and identified N. homalea with protocetraric acid and triterpenes. But this chemotype had not been known in Niebla, nor are depsidones known to be present in N. homalea, nor are they present in any species of Niebla in California; [2] protocetraric acid is found only in N. pulchribarbara, which lacks triterpenes, a rare species that occurs in northern Baja California. [2] In the Lichen Flora of the Greater Sonoran Desert Region, the description given for N. homalea [7] erroneously described the species to have depsidones, including protocetraric acid, which may be confused with salazinic acid when conducting thin-layer chromatography. Salazinic acid is a common lichen substance accessory to triterpenes in species of Vermilacinia, while it may also be noted that the morphology of V. laevigata is easily confused with that of N. homalea. [2]
In view of the controversial classification of this Ramalina complex of genera, and that many of the species are common along the Pacific coast of North America, it may be helpful to conservationists to have molecular studies be conducted to correlate the different views of the species concepts with their DNA, which should include representative specimens from the entire geographic range of the species before drawing definitive conclusions about their synonymy.
Niebla has 42 species distinguished by secondary metabolites (lichen substances) and by morphology. [2] Niebla lichen substances fall into two groups. One group has triterpenes, the other lacks triterpenes. Species of Niebla that contain triterpenes also contain depsides as major lichen substances, which in a species may be either divaricatic acid or sekikaic acid. [2] The group lacking triterpenes contains depsidones as major lichen substances—protocetraric acid, hyprotocetraric acid, salazinic acid, or none of the acids are present in N. homaleoides. Usnic acid, pigments, and other unknown secondary substances are also produced but have little taxonomic value except for one pigment associated with species that produce salazinic acid. The same pigment occurs in the acid-deficient N. homaleoides. [2]
The morphological characters employed to distinguish species of Niebla include the orientation of ridges in the lichen cortex, [9] differences in fragmentation branchlets, which often have black carbonized pycnidia, and the development of specialized asexual propagules referred to as soredia and isidia. [2] Most species occur in Baja California, Mexico. [2]
Niebla is related to Ramalina and Vermilacinia , distinguished from them by the presence of thread-like hyphae intertwined into gelatinized cords called chondroid strands. These strands run lengthwise within the central axis (medulla) of the Niebla thallus, and are visible to the naked eye when a branch of the thallus is sliced or torn. Chondroid strands also protrude into the cortical surface in various network arrangements in which species are recognized by their particular network structure.
Some Ramalina species in the Mediterranean Region have medullary chondroid stands unattached to the medulla; [3] however, they differ from Niebla in having pale pycnidia instead of black pycnidia, and often contain pseudocyphellae and more than one depside or depsidone accompanied by triterpenes and/or bourgeanic acid. [2] Their classification in Ramalina is supported by molecular phylogeny data. [6]
Vermilacinia differs from both Ramalina and Niebla by the absence of chrondroid strands, and by presence of other lichens substances, predominantly terpenes [2] that differ from those in Niebla. Of taxonomic significance is the diterpene (-)-16 α-hydroxykaurane, a rare secondary metabolite in lichens. This diterpene is found only in Vermilacinia within the Ramalinaceae, and also in Roccella (Roccellaceae). [10]
The following lists all the species in the genus Niebla that have been recognized. In bold are those generally accepted. Listed separately are those also treated in the genus Vermilacinia. Species rare or isolated in occurrence are also noted. [2]
Species classified in Niebla also recognized in Vermilacinia
Vermilacinia, a genus of lichenized fungi in the family Ramalinaceae, is a yellow-green fruticose type of lichen with about 30 species that grow on rocks, trees, and soil within the fog zone along the Pacific Coast of North America and South America. The genus name refers to the thallus being divided into narrow worm-like (vermis) branches (lacinia);the latter part of the name (lacinia) generally applied in descriptions and taxonomic keys such as exemplified in a key to Sonoran Desert species of Ramalina.
Niebla homalea is a species of fruticose lichen that grows on rocks in foggy areas along the Pacific Coast of North America, from Mendocino County, California south to Bahía de San Quintín on the main peninsula of Baja California, with an isolated occurrence further south on vertical rock faces above Punta Camachos, and other occurrences in the Channel Islands and on Guadalupe Island. The epithet homalea, given by Acharius, suggests it was in regard to the branches appearing flattened.
Vermilacinia cedrosensis is a species of pale fruticose lichen that is endemic to Baja California, Mexico.
Vermilacinia combeoides is a fruticose lichen found on rocks along the Pacific Coast of North America from Sonoma County, California south to San Quintín, Baja California, and also on Santa Catalina Island and Guadalupe Island.
Vermilacinia laevigata is a fruticose lichen that occurs in the fog zone along the Pacific Coast of the California Floristic Province from Marin County, California to 15 miles south of Misión San Vicente Ferrer in Baja California.
Vermilacinia paleoderma is a pale yellow-green fruticose lichen that occurs commonly along the fog zone of the Pacific Coast of Northern Vizcaíno Desert region of Baja Californica and occasionally in the Chaparral Islands of California.
Vermilacinia procera is a fruticose lichen of local occurrences on rocks near the sea along the Pacific Coast from San Francisco California to the Channel Islands, and to Punta Escarpada in Baja California. The species is also reported to occur further south to the Vizcaíno Peninsula and on Cedros Island, but these reports are controversial in view of different interpretations of the species that include V. pumila and V. paleoderma that were not recognized at the time V. procera was described ; for example, a specimen collected on Guadalupe Island by Weber and MCoy (L-3605, COLO that was cited by Phillip Rundel and Peter Bowler in 1994 as belonging to Niebla procera, whereas in a revision of the genus by Richard Spjut in 1996, it was cited as belonging to Vermilacinia paleoderma. Both authorities generally agree to some extent on the description of the species and its geographical range within the California Floristic Province.
Vermilacinia cephalota is a fruticose lichen usually found on trees, shrubs and wooden fences in the fog regions along the Pacific Coast of North America from southeastern Alaska to the Vizcaíno Peninsula of Baja California.
Vermilacinia leonis is a fruticose lichen usually found on branches of shrubs in the fog regions along the Pacific Coast of North America and South America; in North America it is found on the southern half of the main peninsula of Baja California north to the southern coast of the Vizcaíno Peninsula. In South America, it occurs on bushes and rocks in Chile; reported from Colchaqua (Valley) and Santiago The epithet is in regard to absence of the black transverse bands often seen in other species such as V. leopardina, V. tigrina and V. zebrina.
Vermilacinia tigrina is a fruticose lichen that grows on branches of shrubs and on earth among cactus and shrubs in the fog regions along the Pacific Coast of North America and South America; in North America found in the Channel Islands and near San Diego, California, and in central and southern Baja California; and in South America from Peru to Chile. The epithet is in reference to the irregular black spots or bands on the thallus branches.
Niebla arenaria is a fruticose lichen that grows along the Pacific Coast of North America in the fog regions of the northern peninsula of Baja California from near Colonet south to Morro Santo Domingo. The epithet, arenaria, is in regard to the species growing on sand.
Niebla homaleoides is a fruticose lichen that grows on rocks within a narrow region of the foggy Pacific Coast of Baja California in the Northern Vizcaíno Desert, Arroyo Sauces, Punta Cono and ridges south of Punta Negra. The epithet, homaleoides is in reference to the similarity to Niebla homalea.
Niebla infundibula is a fruticose lichen that grows on rocks along the Pacific Coast in the Channel Islands of California and in Baja California on Guadalupe Island, and on the main peninsula in the southern region of the Northern Vizcaíno Desert on a ridge south of Punta Negra. The epithet, infundibula, is in reference to the funnel shape of the thallus branches.
Niebla josecuervoi is a fruticose lichen that grows on rock, stony soil and sand along the Pacific Coast of northern Baja California from near Misión San Vicente Ferrer to Punta Santa Rosalilillita. The epithet, josecuervoi is in honor of a field assistant, “Jose Cuervo”.
Niebla limicola is a fruticose lichen that grows on barren mud flats and on sand among salt scrub along the Pacific Coast of the Vizcaíno Desert, of Baja California from San Vicente Canyon to Scammon’s Lagoon. The epithet, limicola is in reference to the thallus growing on barren (alkali) soil.
Niebla pulchribarbara is a rare fruticose lichen that occurs on sandy beaches or gravelly soil along the Pacific Coast, at San Antonio del Mar and at Bahía de San Quintín, Baja California. The species epithet, pulchribarbara, is in reference to the strikingly beautiful lichen mat formed by the thallus.
Niebla sorocarpia is a fruticose lichen that grows on rocks along the foggy Pacific Coast of California in the Channel Islands and in Baja California in the Northern Vizcaíno Desert. The epithet, sorocarpia, is in reference to the terminal aggregate apothecia.
Niebla spatulata is a fruticose lichen that grows on small rocks along the foggy Pacific Coast of central Baja California in the Vizcaíno Desert. The epithet, spatulata is in reference to the flattened branches of the thallus, in contrast to another similar species, Niebla flabellata.
Niebla testudinaria is a fruticose lichen that grows on rocks along the foggy Pacific Coast of North America, from Marin County, California to just south of Tijuana in Baja California, in the Channel Islands in California, and Isla San Martín and Guadalupe Island in Baja California The epithet, testudinaria given by William Nylander in 1870, is probably in reference to the dilated branch with a reticulated surface, similar to a tortoise shell.
Niebla undulata is a fruticose lichen that grows on rocks in the fog zone along the Pacific Coast of Baja California in the Northern Vizcaíno Desert, and also in the Channel Islands. The epithet, undulata, is in reference to the wavy margins of the thallus.