Pyrenodesmia micromontana

Pyrenodesmia micromontana
Scientific classification
Domain:	Eukaryota
Kingdom:	Fungi
Division:	Ascomycota
Class:	Lecanoromycetes
Order:	Teloschistales
Family:	Teloschistaceae
Genus:	Pyrenodesmia
Species:	P. micromontana
Binomial name
Pyrenodesmia micromontana (Frolov, Wilk & Vondrák) Hafellner & Türk (2016)
Holotype site: Orenburg, Russia [1]
Synonyms [2]
Caloplaca micromontanaFrolov, Wilk & Vondrák (2016)

Pyrenodesmia micromontana is a species of saxicolous (rock-dwelling), crustose lichen in the family Teloschistaceae. ^[3] Found in the Orenburg region of Russia, this species prefers to grow on lime-rich schist and sandstone boulders and pebbles in scrubs and steppes.

Taxonomy

The lichen was first formally described as a new species in 2016 by the lichenologists Ivan Frolov, Karina Wilk, and Jan Vondrák, who initially classified it in the genus Caloplaca . The type specimen was collected in Russia, specifically in the Orenburg region, within the Sakmara district near the village of Grebeni. This location features a shrubby steppe on the southeast slope of the Grebeni hill, west of the village. The specimen was found at an elevation ranging from 120 to 160 m (390 to 520 ft) above sea level, where it was found growing on lime-rich schist and sandstone boulders and pebbles within a scree. ^[1] Josef Hafellner and Roman Türk transferred the taxon to genus Pyrenodesmia later that year. ^[4]

Description

The thallus of Pyrenodesmia micromontana is epilithic (growing on the rock surface), typically less than 150  μm thick, and shows no distinct cortex . It is ochre or grey in colour, forming small, roundish spots up to 1 cm in diameter or irregular spots spread over several centimetres. The thallus consists of tightly arranged, angular to rounded, flat areoles . The medulla is inconspicuous, with cells containing extracellular crystals that dissolve and recrystallize in sulfuric acid. The algal layer , composed of spherical cells measuring 11.3–15.0 μm in diameter, is usually about 56–68 μm wide. ^[1]

Apothecia in Pyrenodesmia micromontana are small, usually less than 0.4 mm in diameter, with a brown to black disc and exciple , and a thalline exciple matching the thallus colour. The hymenium is colourless, occasionally containing crystals. The epihymenium is grey, sometimes with a weak brown tinge. ^[1]

Chemical spot tests show that the thallus and apothecia are K−, C−, and P−. The uppermost cells in the alveolate cortex of the thallus contain the pigment Sedifolia-grey . ^[1]

Distribution and ecology

Pyrenodesmia micromontana is found in various European and Asian inland territories, usually in mountainous regions. It grows on limestone, lime-rich schist, and sandstone, often accompanied by lichen species such as Acarospora moenium , Polyozosia dispersa , and Sarcogyne regularis . It does not occur in coastal areas where Pyrenodesmia micromarina is found. ^[1]

References

1. Frolov, Ivan; Vondrák, Jan; Fernández-Mendoza, Fernando; Wilk, Karina; Khodosovtsev, Alexander; Halıcı, Mehmet Gökhan (2016). "Three new, seemingly-cryptic species in the lichen genus Caloplaca (Teloschistaceae) distinguished in two-phase phenotype evaluation". Annales Botanici Fennici. 53 (3–4): 243–262. Bibcode:2016AnnBF..53..243F. doi:10.5735/085.053.0413. hdl:10995/117780. S2CID   88825723.
2. "Synonymy. Current Name: Pyrenodesmia micromontana (Frolov, Wilk & Vondrák) Hafellner & Türk, Stapfia 104(1): 173 (2016)". Species Fungorum . Retrieved 22 December 2023.
3. "Pyrenodesmia micromontana (Frolov, Wilk & Vondrák) Hafellner & Türk". Catalogue of Life . Species 2000: Leiden, the Netherlands. Retrieved 22 December 2023.
4. Hafellner, J.; Türk, R. (2016). "Die lichenisierten Pilze Österreichs – eine neue Checkliste der bisher nachgewiesenen Taxa mit Angaben zu Verbreitung und Substratökologie" [The lichenized fungi of Austria – a new checklist of the taxa so far recorded, with data to distribution and substrate ecology](PDF). Stapfia (in German). 104 (1): 130.