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 Lücking, with '' Dictyomeridium proponens'' assigned as the type species. 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 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) ascospores, the lateral ostioles of its ascomata, 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 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
* ''Dictyomeridium campylothelioides'' – Asia
* ''Dictyomeridium immersum'' – Brazil
* ''Dictyomeridium isohypocrellinum'' – Brazil
* ''Dictyomeridium lueckingii'' – Bolivia
* ''Dictyomeridium paraproponens'' – Brazil
* '' Dictyomeridium proponens'' – pantropical
* ''Dictyomeridium tasmanicum'' – Tasmania, Australia

References

{{Taxonbar, from=Q32849581

Trypetheliaceae
Dothideomycetes genera
Lichen genera
Taxa described in 2016
Taxa named by André Aptroot
Taxa named by Robert Lücking