''Lecidea tessellata'' is a species of

saxicolous This glossary of mycology is a list of definitions of terms and concepts relevant to mycology, the study of fungi. Terms in common with other fields, if repeated here, generally focus on their mycology-specific meaning. Related terms can be found ...

(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

Lecideaceae The Lecideaceae are a family (biology), family of lichen-forming fungi in the order Lecideales. It contains about 30 genus, genera and roughly 250 species. A major distinguishing characteristic of the family is the form of the ascomata, fruit ...

. It was

formally described A species description is a formal scientific description of a newly encountered species, typically articulated through a scientific publication. Its purpose is to provide a clear description of a new species of organism and explain how it differ ...

as a species in 1819 by German botanist Heinrich Flörke. In northern North America, it is common and widely distributed, growing on non-calcareous rocks. It also occurs in Afghanistan, China, Nepal, Europe, and Russian Asia. In India, it has been recorded only from the alpine Western Himalayas at an altitude of . Its southern distribution extends to

James Ross Island James Ross Island () is a large island off the southeast side and near the northeastern extremity of the Antarctic Peninsula, from which it is separated by Prince Gustav Channel. Rising to , it is irregularly shaped and extends in a north–so ...

, where it is locally common.

Description

''Lecidea tessellata'' has a chalky white to grey, cracked and areolate

thallus Thallus (: 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. A thallus usually names the entir ...

. Its

apothecia An ascocarp, or ascoma (: ascomata), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. As ...

are black, subimmersed, appressed to adnate and range from 0.5 to 1.8 (–2.0) mm in diameter. The apothecial is smooth, initially rounded in young apothecia, but becomes convex and irregular in mature ones, sometimes with a thin white pruinose layer. The is brownish-green to blackish-green and the is colorless, measuring 40–60

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

in height. The is pale brown and measures 30–40 μm in height, while the is blackish-green externally and colorless internally. The are clavate and measure 30–50 by 8–14 μm, and the ascospores are

ellipsoid An ellipsoid is a surface that can be obtained from a sphere by deforming it by means of directional Scaling (geometry), scalings, or more generally, of an affine transformation. An ellipsoid is a quadric surface; that is, a Surface (mathemat ...

and measure 7–9 by 5–6 μm. ''Lecidea tessellata'' contains confluentic acid, a

lichen product Lichen products, also known as lichen substances, are organic compounds produced by a lichen. Specifically, they are secondary metabolites. Lichen products are represented in several different chemical classes, including terpenoids, orcinol deri ...

that can be detected using

thin-layer chromatography Thin-layer chromatography (TLC) is a chromatography technique that separates components in non-volatile mixtures. It is performed on a TLC plate made up of a non-reactive solid coated with a thin layer of adsorbent material. This is called the sta ...

. Both the thallus and medulla of the lichen have negative reactions with standard chemical spot tests (K−, C−, PD−). '' Lecidea oreophila'', found in the mountains of California's

Sierra Nevada The Sierra Nevada ( ) is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primari ...

, is similar in appearance to ''L. tessellata'', but it has a dark hypothecium and produces 2′-''O''-methylmicrophyllinic acid as the primary lichen product, with or without accessory confluentic acid.

References

{{Taxonbar, from=Q10556093 tessellata Lichen species Lichens described in 1819 Taxa named by Heinrich Gustav Flörke Lichens of China Lichens of Europe Lichens of India Lichens of Western Asia Lichens of North America

Description

See also

References