''Atla recondita'' is a rare alpine species of saxicolous (rock-dwelling),

crustose lichen Crustose lichens are lichens that form a crust which strongly adheres to the Substrate (biology), substrate (soil, rock, tree bark, etc.), making separation from the substrate impossible without destruction. The basic structure of crustose lichen ...

in the family

Verrucariaceae The Verrucariaceae are a family of mostly lichenised fungi in the order Verrucariales. The lichen-forming species, which comprise the vast majority of the family, have a wide variety of thallus forms, and include crustose (crust-like), foliose ( ...

. Found in Sweden, it was formally described as new to science in 2015 by Sanja and Leif Tibell. The

type specimen In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to a ...

was collected from Hamrafjället (

Härjedalen Municipality Härjedalen Municipality (, , no, Herjedalen kommune) is a municipality in Jämtland County in northern Sweden. Its seat is located in Sveg. The municipality roughly, but not exactly, corresponds with the traditional province Härjedalen. The ...

) at an altitude of ; there, it was found growing on

calciferous Calciferous sandstone is a geological term relating to strata at the base of the Carboniferous formation, below the entire sequence of coal measures. This term may be unique to the UK. Typically this part of the geological sequence, as in the Tou ...

rocks. It is known only from a few locations in this area, collected at an altitude range between . The lichen has a thin olive brown-coloured

thallus Thallus (plural: thalli), from Latinized Greek (), meaning "a green shoot" or "twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. Many of these organisms wer ...

and

ascospore An ascus (; ) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera or s ...

s with 9–15 transverse

septa The Southeastern Pennsylvania Transportation Authority (SEPTA) is a regional public transportation authority that operates bus, rapid transit, commuter rail, light rail, and electric trolleybus services for nearly 4 million people in five coun ...

and 3–4 longitudinal septa. The authors note that it is not possible to distinguish this species from the similar ''

Polyblastia ''Polyblastia'' is a genus of lichenized fungi in the family Verrucariaceae. As of 2020, it consists of about 40 species combined with about 50 orphaned species. The main difference with the genus ''Verrucaria'' is related to spores, which are mur ...

'' by

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines *Morphology (archaeology), study of the shapes or forms of artifacts *Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...

alone.

References

Verrucariales Lichen species Lichens described in 2015 Taxa named by Leif Tibell Lichens of Northern Europe {{Eurotiomycetes-stub