''Astrothelium colombiense'' is a species of corticolous (bark-dwelling), crustose lichen in the family Trypetheliaceae. Found in

Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...

, it was formally described as a new species in 2016 by Dutch lichenologist

André Aptroot André Aptroot (Heemskerk, 1961) is a Dutch mycologist and lichenologist. In 1993 he did his PhD at the University of Utrecht under the supervision of Robbert Gradstein (nl). His dissertation was titled "Systematic studies on pyrenocarpous li ...

. The type specimen was collected from the Estacion Forestal La Espriella ( Tumaco, Nariño) at an altitude of . The lichen has shiny, pale ochraceous green thallus with a smooth to somewhat roughened texture. It has a cortex but lacks a prothallus. There is only a single ascospore in each

ascus 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 ...

; this is a rarity in genus '' Astrothelium''. The spores are

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 ...

ellipsoid An ellipsoid is a surface that may be obtained from a sphere by deforming it by means of directional scalings, or more generally, of an affine transformation. An ellipsoid is a quadric surface; that is, a surface that may be defined as the ...

in shape, and muriform (i.e., divided into chambers by multiple transverse and longitudinal septa); they measure 240–300 by 45–50

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 ...

. No lichen products were detected in this species. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

refers to the country of the

type locality Type locality may refer to: * Type locality (biology) * Type locality (geology) See also * Local (disambiguation) * Locality (disambiguation) {{disambiguation ...

References

colombiense Lichen species Lichens described in 2016 Lichens of Colombia Taxa named by André Aptroot {{Dothideomycetes-stub