Niebla flagelliforma explained

Niebla flagelliforma is a fruticose lichen that grows on rocks along the foggy Pacific Coast of Baja California mostly in the Northern Vizcaíno Desert.[1] The epithet, flagelliforma is in reference to the individual branches of the thallus shaped like a flagellum.

Distinguishing features

Niebla flagelliforma is easily recognized by a thallus—up to 6 cm high and 3 cm across—divided from a holdfast into narrow erect branches that terminate—after branching one or more times—in flagelliform branchlets. The cortex of the thallus, which covers a partially hollow medulla, has conspicuous and closely reticulate ridges, often cracking along the transverse ridges, and becomes thinner towards apex, 75–25 μm thick. This thinning of the cortex and the development of a subfistulose medulla probably relates to the coiling of the branches. Black dot-like pycnidia are abundant on the flagelliform branchlets, each pycnidium[2] is surrounded by a cortical margin similar to the thalline margin of an apothecium. The key lichen substance is divaricatic acid (with triterpenes and usnic acid).

Niebla flagelliforma is frequent in wind-sheltered areas inland from the coast on the northern peninsula of Baja California, generally south of Campo Nuevo, but also occurs around Bahía de San Quintín and nearby Isla San Martín.[3]

Taxonomic history

Niebla flagelliforma was recognized as distinct from Niebla homalea, 1 May 1985, following a sample of N. homalea collected 29 April 1985 on Punta Banda in Baja California; N. flagelliforma was collected by Richard Spjut and Richard Marin (S & M 9058A) near Rosarito along Baja Mexico Highway 1, 33 km south of junction with road to Bahía de los Angeles, on rocks of north-facing slopes in the understory of dense brush. A sample of 110 grams was submitted to the National Cancer Institute, Natural Products Branch for their natural product screening program in search of new compounds to treat HIV and cancer; the sample was accessioned as WBA-122, and identified as “Niebla sp. (undscribed) rock ‘ceruchis’ type.”[4] and cited in Spjut's 1996 revision of the genus under N. flagelliforma. The species was described in 1996. It has been since included under an extremely broad interpretation of Niebla homalea;[5] however, this interpretation has been questioned due to inconsistencies in the taxonomic treatment.[6]

External links

Notes and References

  1. Spjut, R. W. 1996. Niebla and Vermilacinia (Ramalinaceae) from California and Baja California. Sida Bot. Misc. 14
  2. Pycnidium (pycnidia plural) is a small flash-shaped structure (200–300 μm wide near the base in Niebla) that produces conidia, which escape through an opening (ostiole) at the top and function in reproduction, asexually or sexually
  3. Isla San Martin, MapCarta, retrieved 22 Dec 2014, http://mapcarta.com/20316724
  4. 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), http://botany.si.edu/colls/collections_overview.htm
  5. Bowler, P. and J. Marsh. 2004. Niebla. ‘Lichen Flora of the Greater Sonoran Desert 2’: 368–380.
  6. Lichen Flora of the Greater Sonoran Desert: Book Review, Richard Spjut, web page, retrieved 22 Dec 2014, http://www.worldbotanical.com/lichen%20flora%20review.htm