Thursday 29 September 2016

Psora altotibetica: a new species of high-altitude Lichen from Mount Everest and the High Himalayas of Nepal & Tibet.

Lichens are hybrid symbiotic organisms, with a 'body' comprised of Fungal hyphae within which can be found cells of an Algal symbiont, and (it has recently been discovered) a third, Bacterial component that somehow facilitates the symbiosis between the other two partners. This unique symbiosis enables lichens to survive in a wide variety of habitats found inhospitable by other organisms, including hot and cold deserts, mountaintops and the high tidal zone on exposed rocky shores, as well as man-made surfaces such as brick and concrete.

In a paper published in the journal MycoKeys on 13 May 2016, Einar Timdal of the Natural History Museum of the University of Oslo, WalterObermayer of the Institut für Pflanzenwissenschaften at Karl-Franzens-Universität Graz, and Mika Bendiksby of the UniversityMuseum at the Norwegian University of Science and Technology, describe a new species of Lichen from the High Himalayas of Nepal and Tibet.

The new species is placed in the genus Psora, which contains about 30 species found on rock and soil from arid areas from the Arctic to the subtropics, and given the specific name altotibetica, from 'altitude' and 'Tibet'. The species was first identified from a preserved specimen at the Herbarium of the Institut für Pflanzenwissenschaften at Karl-Franzens-Universität Graz, collected by Austrian lichenologist Josef Poelt (1924-1995) in 1962 from near the Khumbu Glacier in Nepal, south of Mt Everest, then again in some specimens collected by Torstein Engelskjøn of the Tromsø Museum from the Rongbuk Valley in Tibet, north of Mt Everest, during a joint Chinese-Norwegian scientific expedition in 1993, and subsequently in a number of other specimens collected at altitudes between 4230 and 5000 m in Tibet and stored in the Herbarium of the Institut für Pflanzenwissenschaften.

Psora altotibetica, known distribution. Open circle = holotype locality. Timdal et al. (2016).

Psora altotibetica is a white or off-white encrusting Lichen with black apothacia (cup-shaped fruiting-body that produces spores). It's upper tissues were found to contain crystals of gyrophoric acid and calcium oxalate. A genetic analysis suggests it is closely related to Psora tenuifolia, another Tibetan species, which has been recorded at altitudes of between 2610 and 4525 m.

 Psora altotibetica growing on rock. Scale bar is 1 mm. Timdal et al. (2016).

See also... of Lichen growth on the bones of Homo naledi.                                                    In 2013 scientists in South Africa described the discovery of a remarkable new Hominin species in the Dinaledi Cave System in Gauteng State, South Africa (part of the Maropeng Cradle of Humankind... new species of Lichen-infecting parasitic Fungus from Scandinavia.                                      Lichens are symbiotic organisms, each consisting of a Fungus and an Alga, the Fungus obtaining nutrients from the substrate (surface upon which the Lichen sits), while the Alga produces carbohydrates through photosynthesis. They the Fungi and Algae involved...
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