''Pseudochapsa lueckingii'' is a species of

corticolous 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 ...

(bark-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

Graphidaceae The Graphidaceae are a family of lichen-forming fungi in the order Graphidales. The family contains nearly a hundred genera and more than 2000 species. Although the family has a cosmopolitan distribution, most Graphidaceae species occur in tropic ...

. It is known only from a single collection in

São Paulo São Paulo (; ; Portuguese for 'Paul the Apostle, Saint Paul') is the capital of the São Paulo (state), state of São Paulo, as well as the List of cities in Brazil by population, most populous city in Brazil, the List of largest cities in the ...

, Brazil.

Taxonomy

The lichen was first

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 new species in 2009 by

Klaus Kalb Klaus Kalb (born 1942) is a German lichenologist and an authority on tropical lichens. Born in Nuremberg, he studied at the University of Erlangen–Nuremberg before pursuing a career that significantly advanced the field of lichenology, parti ...

. He collected the

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

from a dense and humid

rainforest Rainforests are forests characterized by a closed and continuous tree Canopy (biology), canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforests can be generally classified as tropi ...

at an elevation of , where it was found growing on the smooth bark of a

deciduous tree In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, after flo ...

. 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 (biology), taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany) ...

honours his colleague

Robert Lücking Robert Lücking (born 1964) is a German lichenologist, known for his extensive research on foliicolous lichens (lichens that live on leaves) and his significant contributions to the taxonomy, ecology, and biodiversity of fungi and lichens. He e ...

, "for his outstanding contributions to tropical lichenology". The

taxon In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

was transferred in 2012 to '' Pseudochapsa'', a segregate genus of '' Chapsa'', characterised by the brown colour of its .

Description

''Pseudochapsa lueckingii'' has a smooth,

olive The olive, botanical name ''Olea europaea'' ("European olive"), is a species of Subtropics, subtropical evergreen tree in the Family (biology), family Oleaceae. Originating in Anatolia, Asia Minor, it is abundant throughout the Mediterranean ...

-green

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 ...

with a 3–10

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 ...

-thick,

hyaline A hyaline substance is one with a glassy appearance. The word is derived from , and . Histopathology Hyaline cartilage is named after its glassy appearance on fresh gross pathology. On light microscopy of H&E stained slides, the extracellula ...

cortical layer The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. It is the largest site of Neuron, neural integration in the central nervous system, and plays ...

. It has large, more-or-less round

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 ...

measuring 0.7–2 mm in diameter with a pale brown covered with white .

Ascospore In fungi, an ascospore is the sexual spore formed inside an ascus—the sac-like cell that defines the division Ascomycota, the largest and most diverse Division (botany), division of fungi. After two parental cell nucleus, nuclei fuse, the ascu ...

s typically have between 5 and 7 transverse

septa SEPTA, the Southeastern Pennsylvania Transportation Authority, is a regional public transportation authority that operates bus, rapid transit, commuter rail, light rail, and electric trolleybus services for nearly four million people througho ...

, and measure 17–25 by 6–7 μm. The lichen contains

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 ''In v ...

as a major metabolite and minor amounts of constictic acid. Kalb suggests that the Panamanian species ''

Pseudochapsa pseudoschizostoma ''Pseudochapsa'' is a genus of lichen-forming fungi in the family Graphidaceae. It has 19 species. It was circumscribed in 2012 by Sittiporn Parnmen, Robert Lücking, and Helge Thorsten Lumbsch, with '' Pseudochapsa dilatata'' as the type species ...

'' is closely related; this species differs from ''P. lueckingii'' in lacking a cortex and in its much smaller apothecia.

References

{{Taxonbar, from=Q22110207 Graphidaceae Lichen species Lichens described in 2009 Taxa named by Klaus Kalb Lichens of Southeast Brazil