Lichenopeltella
Lichenopeltella is a genus of fungi in the family Microthyriaceae. It comprises about 50 species. The genus was established in 1919 by the mycologist Franz Xaver Rudolf von Höhnel, and its classification within fungal families has been revised several times as scientists better understand its relationships. Nearly all species in the genus are specialized parasites that live on lichens rather than forming lichens themselves, often targeting specific host species. These fungi are found worldwide and are recognized by their tiny, shield-like fruiting bodies that develop on the surface of their lichen hosts.
Systematics
Lichenopeltella is a genus of ascomycetous fungi circumscribed by the mycologist Franz Xaver Rudolf von Höhnel in 1919. Höhnel established the genus as monotypic, with Lichenopeltella maculans as the type species. This species was originally described as Microthyrium maculans by Friedrich Wilhelm Zopf in 1898, but Höhnel created Lichenopeltella to accommodate it, reflecting its lichen-associated nature. Over time, many fungi now placed in Lichenopeltella were originally described under other genera such as Actinopeltis, Micropeltis, or Trichothyrina. In fact, most of the "core" species of Lichenopeltella were initially assigned to those genera. Subsequent taxonomic work by Rolf Santesson and others determined that Micropeltis and Trichothyrina are synonyms of Lichenopeltella, leading to numerous recombinations of species into Lichenopeltella.As of 2020 Lichenopeltella included about 48 species worldwide. In the 1990s, the mycologist Paul Diederich significantly expanded the genus by describing 11 new species and providing a key to the 26 lichenicolous species known at that time. The genus name itself reflects its ecology: Lichenopeltella meaning "small lichen shield", in reference to the tiny shield-like fruiting bodies on lichens.
In terms of higher-level classification, Lichenopeltella has had a somewhat unsettled placement. Historically it was included in the family Leptopeltidaceae by Müller & von Arx and others. This was because of its superficial, disk-like ascomata resembling those of Leptopeltis and related genera. However, more recent classifications have revised its position. Lumbsch and Huhndorf left Lichenopeltella as incertae sedis within Dothideomycetes, and a 2011 reappraisal by Wu and colleagues argued that it fits best in the family Trichothyriaceae. This move was based on Lichenopeltellas lichenicolous lifestyle, which it shares with other Trichothyriaceae members. Indeed, the Outline of Fungi treats Lichenopeltellas familial and ordinal placement as unresolved but notes it "may be in Trichothyriaceae". In the 2014 classification of Dothideomycetes, Lichenopeltella is listed under Trichothyriaceae alongside genera like Trichothyrium and Pachythyrium. Thus, while older sources placed it in Microthyriaceae, current consensus leans toward Trichothyriaceae in the order Microthyriales, pending molecular confirmation. A 2012 study suggested merging Lichenopeltella into the plant-pathogenic genus Kellermania, but later researchers rejected that, maintaining Lichenopeltella as distinct.
Habitat, distribution, and ecology
Nearly all Lichenopeltella species are lichenicolous fungi, meaning they live on lichens. They do not form lichens themselves but instead grow on the surface of lichen hosts as parasites or commensals. Lichenopeltella has been recorded on a wide variety of lichen hosts, usually exhibiting high host-specificity: many species infect only a single lichen genus or even a single host species. For example, Lichenopeltella coppinsii was discovered growing on the crustose lichen species Verrucaria muralis in England. Lichenopeltella heterodermiicola infects the foliose lichen Heterodermia speciosa, with occurrences reported in Arkansas and Ecuador. Lichenopeltella arctomiae and L. biatorae, described in 2009, parasitize specific microlichens in the Pacific Northwest of North America. Other hosts documented include Cladonia, Lobaria, Hypogymnia, Peltigera, Thelidium, Heppia, and more, spanning multiple lichen families. By the late 1990s, at least 26 lichenicolous species of Lichenopeltella were known worldwide, and the number has since grown to around 50 species with new discoveries in Europe, North America, Asia, and beyond.Fossil record
Lichenopeltella has a substantial temporal range: a fossil species has been described from ancient deposits. Lichenopeltella mizerniana, described in 2020, was discovered in Upper Pliocene sediment from southern Poland. The fossil consisted of minute, shield-shaped fruiting bodies covered with stiff, hair-like bristles on a leaf, closely resembling modern Lichenopeltella in structure.Species
, Species Fungorum accepts 51 species of Lichenopeltella.- Lichenopeltella alpestris
- Lichenopeltella ammophilae
- Lichenopeltella arctomiae
- Lichenopeltella biatorae
- Lichenopeltella bunodophoronis
- Lichenopeltella cetrariae
- Lichenopeltella cetrariicola
- Lichenopeltella cladoniarum
- Lichenopeltella communis
- Lichenopeltella coppinsii
- Lichenopeltella cupularum
- Lichenopeltella epiphylla
- Lichenopeltella fimbriata
- Lichenopeltella heppiae
- Lichenopeltella heterodermiae
- Lichenopeltella heterodermiicola
- Lichenopeltella hydrophila
- Lichenopeltella hypogymniae
- Lichenopeltella hypotrachynae
- Lichenopeltella leprosulae
- Lichenopeltella leptogii
- Lichenopeltella lobariae
- Lichenopeltella maculans
- Lichenopeltella megalosporae
- Lichenopeltella microspora
- Lichenopeltella minuta
- Lichenopeltella mizerniana
- Lichenopeltella mobergii
- Lichenopeltella nigroannulata
- Lichenopeltella norfolciana
- Lichenopeltella palustris
- Lichenopeltella pannariacearum
- Lichenopeltella peltigericola
- Lichenopeltella physciae
- Lichenopeltella pinophylla
- Lichenopeltella pseudocyphellariae
- Lichenopeltella quinquecladiopsis
- Lichenopeltella ramalinae
- Lichenopeltella rangiferinae
- Lichenopeltella salicis
- Lichenopeltella santessonii
- Lichenopeltella sclerenchymatica
- Lichenopeltella setifera
- Lichenopeltella soiliae
- Lichenopeltella stereocaulorum
- Lichenopeltella swaminathaniana
- Lichenopeltella thalamica
- Lichenopeltella thamnoliae
- Lichenopeltella thelidii
- ''Lichenopeltella uncialicola''