Niebla Flabellata

''Niebla flabellata '' is a fruticose lichen that grows on rocks along the foggy Pacific Coast of Baja California in the Northern Vizcaíno Desert, from San Fernando Canyon to the northern shore of the Vizcaíno Peninsula west to Cedros Island.Spjut, R. W. 1996. ''Niebla'' and ''Vermilacinia'' (Ramalinaceae) from California and Baja California. Sida Bot. Misc. 14 The epithet, '' flabellata '' is in reference to the flattened branches of the thallus.

Distinguishing features

''Niebla flabellata '' is characterized by a fragile thallus divided into irregularly flattened branches spreading from a holdfast, to 7 cm high and 6 cm across, and by containing the lichen substance salazinic acid (without triterpenes; with consalazinic acid, sabrosin derivative), and by its relatively thin cortex, 25–50 μm thick, in contrast to 45–75 μm thick in '' Niebla josecuervoi'', which also differs by the cylindrical-prismatic branches. The branches of ''N. flabellata'' rarely show any definite shape, varying from almost entirely ribbon-like, to often partly ribbon-like with irregularly dilated parts, or mostly dilated and variously torn along the margins. Black dot like pycnidia are common and conspicuous along the branch margins, on the cortical ridges, and at the branch tips, undoubtedly due to the relatively thin cortex. The species will mostly likely be confused with '' Niebla effusa'', one that differs by having a rigid thallus that grows on ground instead on rocks, features that are associated with a thicker cortex (35–75 μm thick) and by the absence of a central attachment holdfast (in spreading over the ground).

''Niebla flabellata'' is one of the common pebble lichens in the ''Niebla'' communities found along the northern coastal peninsula of Baja California south of Campo Nuevo, but it also occurs on rocks of canyon walls of arroyos, and on calcareous ridges.

On Cedros Island, and in the Sierra Hornitos on the Vizcaíno Peninsula, and near Rosarito towards the southern end of the northern peninsula of Baja California, '' Niebla spatulata'' is recognized as a rare species that occurs with ''N. flabellata''. It differs by having the lichen substance hypoprotocetraric acid. The two species appear to represent one of the few examples of sibling species in the genus.

Also along the northern Vizcaíno Peninsula is ''Niebla limicola'', a species that has the flattened branch morphology of ''N. flabellata'', the short bifurcate branchlets of '' Niebla arenaria'', and the terricolous lichen habit of '' Niebla effusa'', all which contain salazinic acid. It is found mainly along the barren tidal flats and on dunes with coastal salt scrub.

Taxonomic history

''Niebla flabellata'' was first collected just north of Punta Santa Rosalillita (vicinity of Rancho San Andrés, 2 May 1985, as part of a 100 gram sample that largely contained '' Niebla caespitosa'' to be submitted for anti-HIV screening by the National Cancer Institute, but the sample was not immediately submitted because it contained thalli of ''N. flabellata'' and '' Niebla flagelliforma''; the former is distinguished by having salazinic acid as indicated above, the latter with divaricatic acid and terminal flagelliform branchlets;. The entire sample was analyzed by thin-layer chromatography from which 55 grams of '' Niebla caespitosa'' were later submitted (14 Nov 1985) to the National Cancer Institute (NCI) Natural Products Branch, among 63 other lichen samples, 59 of which were from Oregon. The sample was accessioned as WBA-202 with reference to the collection number S & M 9073 (for Richard Spjut & Richard Marin), identified as ''Niebla'' aff. ''testudinaria''.Samples of lichens were collected from the Eastern and Western regions of the United States and Baja California, Mexico during 1985 for anti-HIV screening. Prior to 1982, samples for antitumor screening were supplied in 1 kilogram (kg) quantity (dried) to the NCI by the USDA Agricultural Research Service. In October 1982, the funding for this cooperative agreement was terminated. World Botanical Associates (WBA) was formed by Richard Spjut in May 1983 to continue to supply samples for antitumor screening. Lichens were considered a potential novel source for new anti-HIV drugs since they had rarely been collected for the NCI antitumor screening program. Richard Spjut, the Senior Partner of WBA, proposed that the NCI reduce their 1 kg quantity to 25 grams in order to obtain a broad diversity of lichen samples. The NCI group maintains an inventory of natural product extracts with details on the collection data. Voucher specimens are deposited at the United States National Herbarium (Smithsonian Institution) and cited in Spjut's 1996 revision of the genus under ''N. caespitosa''.

It may be noted that ''Niebla flabellata'' has been treated as belonging to a broad spectrum of morphological and chemical variation under a single species, '' Niebla josecuervoi'', which includes all the other species of ''Niebla'' mentioned above and more.Bowler, P. and J. Marsh. 2004. ''Niebla''. ‘Lichen Flora of the Greater Sonoran Desert 2’: 368–380.

References

External links

*World Botanical Associates, ''Niebla flabellata'', retrieved 22 Dec 2014, http://www.worldbotanical.com/niebla_flabellata.htm#flabellata

{{Taxonbar, from=Q20720362

Lichen species
Lichens of North America
Ramalinaceae
Lichens described in 1996
Taxa named by Richard Wayne Spjut