''Dictyomeridium'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

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 ...

s in the family

Trypetheliaceae The Trypetheliaceae are a family of mainly lichen-forming fungi in the order Trypetheliales. The family consists almost exclusively of corticolous (bark-dwelling), crustose lichens with an almost strictly tropical distribution. Taxonomy Trypethe ...

. It has nine species.

Taxonomy

The genus was

circumscribed In geometry, a circumscribed circle for a set of points is a circle passing through each of them. Such a circle is said to ''circumscribe'' the points or a polygon formed from them; such a polygon is said to be ''inscribed'' in the circle. * Circum ...

in 2016 by lichenologists

André Aptroot André Aptroot ( Heemskerk, 1961) is a Dutch mycologist and lichenologist. His primary research focus is on biodiversity, particularly tropical lichens, encompassing systematics, floristic surveys, and taxonomic reviews. A prolific research ...

, Matthew Nelson, and

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 ...

, with '' Dictyomeridium proponens'' assigned as the

type species In International_Code_of_Zoological_Nomenclature, 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 spe ...

. The seven species they included in the genus were mostly previously classified in the genus '' Polymeridium'', while the type species was known by different names in the genus '' Campylothelium''.

Phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

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 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, 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 wikt:ostium, "ostium", "opening". The term is also used in higher plants, for example to denote the opening of the ...

s of its

ascomata An ascocarp, or ascoma (: ascomata), is the fruiting body (sporocarp (fungi), sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded ascus, asci, each of which typically contains four to ...

, 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 powder used to add or alter color or change visual appearance. Pigments are completely or nearly solubility, insoluble and reactivity (chemistry), chemically unreactive in water or another medium; in contrast, dyes are colored sub ...

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'' –

pantropical A pantropical ("all tropics") distribution is one which covers tropical regions of both the Eastern and Western hemispheres. Examples of species include caecilians, modern sirenians and the plant genera ''Acacia'' and ''Bacopa''. ''Neotropical' ...

* '' Dictyomeridium campylothelioides'' – Asia * '' Dictyomeridium immersum'' – Brazil * ''

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

'' – Brazil * '' Dictyomeridium lueckingii'' – Bolivia * '' Dictyomeridium neureuterae'' – New Zealand * '' Dictyomeridium paraproponens'' – Brazil * '' Dictyomeridium proponens'' – pantropical * '' Dictyomeridium tasmanicum'' –

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

, Australia

References

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