''Parvoplaca tiroliensis'' is a species of crustose lichen in the family

Teloschistaceae The Teloschistaceae are a large family of mostly lichen-forming fungi belonging to the class Lecanoromycetes in the division Ascomycota. The family, estimated to contain over 1800 species, was extensively revised in 2013, including the creation o ...

, and the type species of the genus ''

Parvoplaca ''Parvoplaca'' is a genus of lichen-forming fungi in the family Teloschistaceae. The genus was circumscription (taxonomy), circumscribed in 2013 by Ulrik Søchting, Patrik Frödén, and Ulf Arup. Species *''Parvoplaca athallina'' *''Parvoplaca ...

''. It is widely distributed, and has been recorded growing on a variety of , including moss, dead plant material, and bone.

Taxonomy

The lichen was formally described as a species new to science in 1903 by the Austrian-Hungarian lichenologist

Alexander Zahlbruckner Alexander Zahlbruckner (31 May 1860, Svätý Jur – 1938, Vienna) was an Austrian- Hungarian botanist who specialized in the study of lichens. Johann Babtist Zahlbruckner, an earlier Austrian botanist, was his grandfather. From 1878 to 1883 ...

, who initially classified it in the genus ''

Caloplaca ''Caloplaca'' is a lichen genus comprising a number of distinct species. Members of the genus are commonly called firedot lichen, jewel lichen.Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, gold lichens, "ora ...

''. Ulf Arup and colleagues transferred the taxon to the genus ''

'' in 2013, following a molecular phylogenetics-based restructuring of the family

Description

''Parvoplaca tirolensis'' is a muscicolous lichen, characterised by a thallus that tends to be obscured or blend into the

moss Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) '' sensu stricto''. Bryophyta (''sensu lato'', Schimp. 1879) may also refer to the parent group bryophytes, which comprise liverworts, mosses, and hor ...

it grows upon. The apothecia (fruiting bodies) of this species are dispersed and sessile, typically measuring about 0.2 mm in diameter, though they can reach up to 0.3 mm. In its early stages, the of the apothecia is flat to slightly concave and has a yellow hue with a greenish tinge. As it matures, the disc turns to an

olive The olive, botanical name ''Olea europaea'', meaning 'European olive' in Latin, is a species of small tree or shrub in the family Oleaceae, found traditionally in the Mediterranean Basin. When in shrub form, it is known as ''Olea europaea'' ...

colour, retaining a yellowish tinge. The margin of the apothecia is thick and prominent, initially yellow before becoming more or less the same colour as the disc. The lateral margins, however, often retain a more pronounced yellow colour. The of the apothecia is abundant in algae. The has a fan-shaped structure made of , cells. The of ''Parvoplaca tirolensis'' is

hyaline A hyaline substance is one with a glassy appearance. The word is derived from el, ὑάλινος, translit=hyálinos, lit=transparent, and el, ὕαλος, translit=hýalos, lit=crystal, glass, label=none. Histopathology Hyaline cartilage is ...

and contains oil droplets. The

hymenium The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in others some ...

measures between 70 and 100

μm The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

and is characterized by medium coarse . The

paraphyses Paraphyses are erect sterile filament-like support structures occurring among the reproductive apparatuses of fungi, ferns, bryophytes and some thallophytes. The singular form of the word is paraphysis. In certain fungi, they are part of the fe ...

are slender, measuring 0.5–1 μm, and are sparsely branched at the apex. The upper cells are enlarged, about 4–6 μm thick, and constricted at the septa. The

asci ASCI or Asci may refer to: * Advertising Standards Council of India * Asci, the plural of ascus, in fungal anatomy * Accelerated Strategic Computing Initiative * American Society for Clinical Investigation * Argus Sour Crude Index * Association of ...

of this species typically contain eight spores. The spores themselves are sized 17–19 by 9–12 μm, with a

septum In biology, a septum (Latin for ''something that encloses''; plural septa) is a wall, dividing a cavity or structure into smaller ones. A cavity or structure divided in this way may be referred to as septate. Examples Human anatomy * Interatri ...

measuring 4–4.5 μm.

Similar species

Athallia saxifragarum ''Athallia'' is a genus of fungi belonging to the family Teloschistaceae. It was first described in 2013 by Ulf Arup, Patrik Frödén, and Ulrik Søchting, and the type species is '' Athallia holocarpa''. The genus name means without a thallus. ...

'' is a similar species with which ''Parvoplaca tirolensis'' might be confused. The former lichen is distinguished by its somewhat larger (0.4–1.0 mm wide) and more orange-coloured apothecial discs, and smaller ascospores (12–15 by 5–8 μm).

Distribution

The lichen was reported from Iran in 2022, where it was found growing on the oak tree bark in Mawat. In Greenland, it has been recorded on old bone in addition to plant remains, the latter substrate together with ''

Caloplaca cerina ''Caloplaca'' is a lichen genus comprising a number of distinct species. Members of the genus are commonly called firedot lichen, jewel lichen.Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, gold lichens, "or ...

''.

References

{{Taxonbar, from=Q25894006 , from2=Q10440565 Teloschistales Lichen species Lichens described in 1903 Lichens of Subarctic America Lichens of Europe Lichens of Western Asia Taxa named by Alexander Zahlbruckner