''Astrothelium variabile'' is a species of corticolous (bark-dwelling) lichen in the family

Trypetheliaceae The Trypetheliaceae are a family of mainly lichen-forming fungi in the order Trypetheliales. Genera *'' Alloarthopyrenia'' – 1 sp. *'' Aptrootia'' – 3 spp. *'' Architrypethelium'' – 8 spp. *''Astrothelium'' – ca. 275 spp. *'' Bathel ...

. Found in Bolivia, it was formally described as a new species in 2016 by lichenologists Adam Flakus and

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 l ...

. The

type specimen In biology, a type is a particular 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 anchor or centralizes the ...

was collected near the biological station in the Beni Biological Station Biosphere Reserve (

Yacuma Province Yacuma is a province in the Beni Department in Bolivia. Its seat is Santa Ana del Yacuma. Subdivision Yacuma Province is divided into two municipalities A municipality is usually a single administrative division having corporate status ...

Beni Department Beni (), sometimes El Beni, is a northeastern department of Bolivia, in the lowlands region of the country. It is the second-largest department in the country (after Santa Cruz), covering 213,564 square kilometers (82,458 sq mi), and it was cre ...

) at an altitude of ; there, in a lowland

Amazon forest The Amazon rainforest, Amazon jungle or ; es, Selva amazónica, , or usually ; french: Forêt amazonienne; nl, Amazoneregenwoud. In English, the names are sometimes capitalized further, as Amazon Rainforest, Amazon Forest, or Amazon Jungle. ...

, it was found growing on bark in

Beni savanna The Beni savanna, also known as the Llanos de Moxos or Moxos plains, is a tropical savanna ecoregion of the Beni Department of northern Bolivia. Setting The Beni savanna covers an area of in the lowlands of northern Bolivia, with small portio ...

. It is only known to occur in this type of habitat in Bolivia. The

species epithet Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany) A botanical name ...

''variabile'' alludes to the variable amounts of

lichexanthone Lichexanthone is an organic compound in the structural class of chemicals known as xanthones. Lichexanthone was first isolated and identified by Japanese chemists from a species of leafy lichen in the 1940s. The compound is known to occur in ma ...

in different regions of the

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 ...

. This is 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 de ...

that causes parts of the lichen to

fluoresce Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore a lower photon energy, tha ...

when lit with a long-wavelength

UV light Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation i ...

. ''

Astrothelium ochroleucoides ''Astrothelium ochroleucoides'' is a species of corticolous (bark-dwelling) lichen in the family Trypetheliaceae. It is found in Brazil and Guyana. Taxonomy ''Astrothelium ochroleucoides'' was first described in 2016 by lichenologists Andr� ...

'' is somewhat similar in external appearance, but it has smaller ascospores than ''A. variabile''.

References

variabile Lichen species Lichens described in 2016 Lichens of Bolivia Taxa named by André Aptroot Taxa named by Adam Grzegorz Flakus {{Dothideomycetes-stub