''Dictyomeridium'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

of corticolous (bark-dwelling),

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 ...

s 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 ...

. It has eight species.

Taxonomy

The genus was

circumscribed In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius. Not every po ...

in 2016 by lichenologists

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 ...

, Matthew Nelson, and

Robert Lücking Robert Lücking (born 1964) is a German lichenologist. He is a leading expert on foliicolous lichens–lichens that live on leaves. Life and career Born in Ulm in 1964, Lücking earned both his master's (1990) and PhD degree (1994) at the Univer ...

, with ''

Dictyomeridium proponens ''Dictyomeridium'' is a genus of corticolous (bark-dwelling), crustose lichens in the family Trypetheliaceae. It has eight species. Taxonomy The genus was circumscribed in 2016 by lichenologists André Aptroot, Matthew Nelson, and Robert Lü ...

'' assigned as the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen( ...

. The seven species they included in the genus were mostly previously classified in the genus ''

Polymeridium ''Polymeridium'' is a genus of fungi in the family Trypetheliaceae. The genus was originally circumscribed as a section of the genus ''Arthopyrenia'' by Swiss lichenologist Johannes Müller Argoviensis in 1883. Richard Harris elevated it to gener ...

'', while the type species was known by different names in the genus ''

Campylothelium ''Astrothelium'' is a genus of corticolous (bark-dwelling) lichens in the family Trypetheliaceae. The genus was circumscribed in 1824 by German botanist Franz Gerhard Eschweiler, with ''Astrothelium conicum'' assigned as the type species. Sp ...

''.

Phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

analysis showed that the group of species was distant from the core group of their previous genus. An eight species, from Australia, was added to the genus in 2022.

Description

''Dictyomeridium'' is distinguished from other genera in the family Trypetheliaceae by its (multichambered)

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, the lateral

ostiole An ''ostiole'' is a small hole or opening through which algae or fungi release their mature spores. The word is a diminutive of "ostium", "opening". The term is also used in higher plants, for example to denote the opening of the involuted ...

s of its

ascomata 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 ...

, and several subtle microscopic differences in the form of the and the ascospores. ''Dictyomeridium'' species are distinguished from each other by their reaction to the , the dimensions of their spores, and by the presence or absence of a red

pigment A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic comp ...

in their ostioles. All species lack a , and have conical to ascomata with eccentric (i.e., not placed centrally) ostioles. Sometimes, are present.

Species

* ''

Dictyomeridium amylosporum ''Dictyomeridium'' is a genus of corticolous lichen, corticolous (bark-dwelling), crustose lichens in the family Trypetheliaceae. It has eight species. Taxonomy The genus was circumscription (taxonomy), circumscribed in 2016 by lichenologists A ...

'' –

pantropical A pantropical ("all tropics") distribution is one which covers tropical regions of both hemispheres. Examples of species include caecilians, modern sirenians and the plant genera ''Acacia'' and '' Bacopa''. '' Neotropical'' is a zoogeographic t ...

* ''

Dictyomeridium campylothelioides ''Dictyomeridium'' is a genus of corticolous (bark-dwelling), crustose lichens in the family Trypetheliaceae. It has eight species. Taxonomy The genus was circumscribed in 2016 by lichenologists André Aptroot, Matthew Nelson, and Robert Lück ...

'' – Asia * ''

Dictyomeridium immersum ''Dictyomeridium'' is a genus of corticolous (bark-dwelling), crustose lichens in the family Trypetheliaceae. It has eight species. Taxonomy The genus was circumscribed in 2016 by lichenologists André Aptroot, Matthew Nelson, and Robert Lück ...

'' – Brazil * ''

Dictyomeridium isohypocrellinum ''Dictyomeridium'' is a genus of corticolous lichen, corticolous (bark-dwelling), crustose lichens in the family Trypetheliaceae. It has eight species. Taxonomy The genus was circumscription (taxonomy), circumscribed in 2016 by lichenologists A ...

'' – Brazil * ''

Dictyomeridium lueckingii ''Dictyomeridium'' is a genus of corticolous (bark-dwelling), crustose lichens in the family Trypetheliaceae. It has eight species. Taxonomy The genus was circumscribed in 2016 by lichenologists André Aptroot, Matthew Nelson, and Robert Lück ...

'' – Bolivia * ''

Dictyomeridium paraproponens ''Dictyomeridium'' is a genus of corticolous (bark-dwelling), crustose lichens in the family Trypetheliaceae. It has eight species. Taxonomy The genus was circumscribed in 2016 by lichenologists André Aptroot, Matthew Nelson, and Robert Lü ...

'' – Brazil * ''

'' – pantropical * ''

Dictyomeridium tasmanicum ''Dictyomeridium'' is a genus of corticolous lichen, corticolous (bark-dwelling), crustose lichens in the family Trypetheliaceae. It has eight species. Taxonomy The genus was circumscription (taxonomy), circumscribed in 2016 by lichenologists A ...

'' –

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

, Australia

References

{{Taxonbar, from=Q32849581 Trypetheliaceae Dothideomycetes genera Lichen genera Taxa described in 2016 Taxa named by André Aptroot Taxa named by Robert Lücking