''Chaenothecopsis kilimanjaroensis'' is a species of

lichenicolous 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 ...

(lichen-dwelling)

pin lichen Lichens are symbiotic organisms made up of multiple species: a fungus, one or more photobionts (an alga and/or a cyanobacteria) and sometimes a yeast. They are regularly grouped by their external appearance – a characteristic known as their gro ...

in the family

Mycocaliciaceae The Mycocaliciaceae are a family (biology), family of fungi in the order Mycocaliciales, comprising seven genera and approximately 90 species. Originally proposed in 1970 by Alexander Schmidt, the family is characterised by immersed thallus, thal ...

. Found in the

cloud forest A cloud forest, also called a water forest, primas forest, or tropical montane cloud forest, is a generally tropical or subtropical, evergreen, Montane forest, montane, Tropical and subtropical moist broadleaf forests, moist forest characteri ...

s of

Tanzania Tanzania, officially the United Republic of Tanzania, is a country in East Africa within the African Great Lakes region. It is bordered by Uganda to the northwest; Kenya to the northeast; the Indian Ocean to the east; Mozambique and Malawi to t ...

, it was described as a new species in 2019. These tiny lichens have a short stalk, which can be either single or formed in aggregates on the same thallus. The stalks are medium brown at the base and become translucent in water. This species has unique spores, which contain a single

septum In biology, a septum (Latin language, Latin for ''something that encloses''; septa) is a wall, dividing a Body cavity, cavity or structure into smaller ones. A cavity or structure divided in this way may be referred to as septate. Examples Hum ...

(internal partition), are arranged in a single row in the

ascus An ascus (; : asci) 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 gen ...

, and have a surface ornamented with elongated, blister-like structures.

Taxonomy

The lichen 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 new species in 2019 by Stella Temu and

Leif Tibell Leif Tibell (born 16 November 1944) is a Swedish lichenologist and Emeritus Professor at the University of Uppsala. He is known for his expertise on calicioid lichens. He was awarded the Acharius Medal in 2012 for lifetime achievements in lich ...

. 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 ...

was collected by the first author from the Monduli Forest Reserve (

Arusha Arusha is a city in Tanzania. The city is the Capital city, capital of the Arusha Region. It has a population of 617,631 people.

) at an elevation of .

Molecular phylogenetics Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

analysis using

internal transcribed spacer Internal transcribed spacer (ITS) is the spacer DNA situated between the small-subunit ribosomal RNA (rRNA) and large-subunit rRNA genes in the chromosome or the corresponding transcribed region in the polycistronic rRNA precursor transcript. ...

DNA sequences indicates that ''Chaenothecopsis kilimanjaroensis'' is closely related to ''

Chaenothecopsis debilis ''Chaenothecopsis'' is a genus of about 40 species of pin lichens in the family Mycocaliciaceae. Taxonomy The genus was circumscribed in 1927 by Finnish lichenologist Edvard August Vainio, with '' Chaenothecopsis rubescens'' assigned as the ...

''.

Description

''Chaenothecopsis kilimanjaroensis'' features a

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 ...

that grows as either a

commensal Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit f ...

parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...

on sterile lichen crusts or on the thallus of '' Chaenotheca chloroxantha''. The

host A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County * Host Island, in the Wilhelm Archipelago, Antarctica People * ...

lichen tends to lose

pigmentation A pigment is a powder used to add or alter color or change visual appearance. Pigments are completely or nearly insoluble and chemically unreactive in water or another medium; in contrast, dyes are colored substances which are soluble or go in ...

and turn mauve-grey when it is parasitised. The

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 ...

(fruiting bodies) of ''C. kilimanjaroensis'' are very short-stalked or with medium-long, olivaceous brown stalks, measuring 0.21–0.27 mm in height. The (the cup-shaped apothecium on the top of the stalk) can be either single and lens-shaped to broadly

obconic In botany, an obconic is an inverted cone shape. The term is most frequently applied to certain fruit or hypanthium structures with the apical end attached to the stem; however, less frequently the usage may apply to the pistil structure. In the ca ...

al, or it may form 2–5 aggregated units on the same, usually short, stalk. The is dark brown, with an intricate structure composed of intertwined fungal

hypha A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one o ...

e. The asci (spore-bearing cells) are cylindrical, containing spores that are arranged in a single row and feature a thickened apex penetrated by a fine canal. The spores themselves 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 ...

al to narrowly ellipsoidal, pale brown, and measure 6–6.9

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 length and 2.1–2.6 μm in width. These spores are distinct for their poorly pigmented

and minutely ornamentation, which is composed of tiny, often slightly elongated blister-like . This feature is barely visible with

light microscopy Microscopy is the technical field of using microscopes to view subjects too small to be seen with the naked eye (objects that are not within the resolution range of the normal eye). There are three well-known branches of microscopy: optical, el ...

, but becomes evident when viewed with

scanning electron microscopy A scanning electron microscope (SEM) is a type of electron microscope that produces images of a sample by scanning the surface with a focused beam of electrons. The electrons interact with atoms in the sample, producing various signals that ...

(SEM).

Similar species

''Chaenothecopsis kilimanjaroensis'' shares some characteristics with other ''

Chaenothecopsis ''Chaenothecopsis'' is a genus of about 40 species of pin lichens in the family Mycocaliciaceae. Taxonomy The genus was circumscribed in 1927 by Finnish lichenologist Edvard August Vainio, with '' Chaenothecopsis rubescens'' assigned as the typ ...

'' species, such as '' C. consociata'', '' C. epithallina'', and '' C. formosa'', in that it behaves as a parasite or commensal on the thalli of its host lichens. Its variable ascoma morphology and the structure of its apothecia make it a unique species within the genus. It resembles '' C. pusilla'' in having a pale olivaceous brown stalk that is translucent in water, but differs in its host preference and spore septation. It also recalls '' C. amurense'' in its irregularly aggregated capitula but is distinguished by its host species and spore type.

Habitat and distribution

This species was discovered growing on the trunks of ''

Nuxia congesta ''Nuxia congesta'', commonly known as brittle-wood, is a species of tree in the Stilbaceae family, with an extensive range in the Afrotropics. The species is named ''congesta'' for its dense inflorescences. Range The species is native to Eswati ...

'' trees in the montane

s of Tanzania. At the time of its original publication, it was only known to occur in the Monduli forest reserve in Arusha, Tanzania.

References

{{Taxonbar, from=Q124250680 Eurotiomycetes Lichen species Lichens described in 2019 Lichens of East Tropical Africa Lichenicolous lichens Taxa named by Leif Tibell