''Pertusaria aptrootii'' is a species of

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

in the family

Pertusariaceae The Pertusariaceae are a family of lichen-forming fungi in the order Pertusariales. Taxonomy The family was formally circumscribed by German lichenologist Gustav Wilhelm Körber in 1846. It contained the genera ''Pertusaria'' and '' Ochrolechia ...

. It was described as a new species in 1998 by

Alan W. Archer Alan W. Archer (born 1930) is a mycologist and taxonomist. He is currently (January 2021) an honorary research associate at Royal Botanic Gardens Sydney. He uses chemotaxonomy as well as morphological features in taxonomy and to devise keys, ...

and

John Alan Elix John Alan (Jack) Elix (born 1941) emeritus professor in chemistry at the Australian National University, is an organic chemist who has contributed in many fields: lichenology, lichen chemotaxonomy, plant physiology and biodiversity and natural p ...

. The lichen occurs in

Papua New Guinea Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...

, and is known from only two specimens collected at the

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

. The

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * Ty ...

was collected in Varirata National Park at an altitude of , where it was found growing on

conglomerate rock Conglomerate () is a clastic sedimentary rock that is composed of a substantial fraction of rounded to subangular gravel-size clasts. A conglomerate typically contains a matrix of finer-grained sediments, such as sand, silt, or clay, which fills ...

. It is named after 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 l ...

, who collected the type. The lichen has a dull

fawn Deer or true deer are hoofed ruminant mammals forming the family (biology), family Cervidae. The two main groups of deer are the Cervinae, including the muntjac, the elk (wapiti), the red deer, and the fallow deer; and the Capreolinae, inclu ...

, thick, crustose

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 ...

that is cracked and areolate (divided into small, usually rounded to polygonal to irregular areas). It has numerous wart-shaped

apothecia An ascocarp, or ascoma (), 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. Ascocarps are mo ...

that are 1–2 mm in diameter. Between two and four point-like, black ostioles (pore-like openings through which the spores escape) are on each apothecium. ''Pertusaria aptrootii'' makes

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 o ...

s that are

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 ...

, smooth, and measure 108–125

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 Uni ...

long by 37–48 μm wide. They invariably number four per

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 o ...

, in contrast to some other ''

Pertusaria ''Pertusaria'' is a large genus of warty crustose lichens in the Pertusariaceae family.Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, The fruiting bodies are usually modified apothecia that immersed in warts ...

'' species found in the same country, which may occasionally have asci with three or five ascospores. Characteristic secondary chemicals found in the lichen include 2-chlorolichexanthone, 2-''O''-methylsuperlatolic acid, and

stictic acid Stictic acid is an aromatic organic compound, a product of secondary metabolism in some species of lichens. Stictic acid is the subject of preliminary biomedical research. Stictic acid has cytotoxic and apoptotic effects ''in vitro''. Computation ...

References

{{Taxonbar, from=Q21312086 aptrootii Lichen species Lichens described in 1998 Lichens of New Guinea Taxa named by John Alan Elix