Xanthopyreniaceae
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Zahlbr. (1926)
| Xanthopyreniaceae | |
|---|---|
_F._Mohr_545932.jpg) | |
| Collemopsidium foveolatum in Lourinhã, Portugal | |
Scientific classification  | |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Dothideomycetes |
| Order: | Collemopsidiales |
| Family: | Xanthopyreniaceae Zahlbr. (1926) |
| Type genus | |
| Xanthopyrenia | |
| Genera | |
|
Collemopsidium | |
The Xanthopyreniaceae are a family of lichen-forming fungi in the order Collemopsidiales. Members of this family are found worldwide on rocks in various climates, from temperate to polar regions, where they form inconspicuous crusty growths or live hidden within the rock surface. Where lichenised, species partner with cyanobacteria, and several lineages are parasitic (lichenicolous) on other lichens. The family is characterized by small, dark fruiting bodies that release spores through a single opening at the top.
The family was circumscribed by the lichenologist Alexander Zahlbruckner in 1926.[2]
In 1988, David Hawksworth and Ove Eriksson proposed conserving the name Arthopyreniaceae and rejecting Xanthopyreniaceae (nom. cons. prop.; nom. rej. prop.). They argued that usage in the literature overwhelmingly favoured Arthopyreniaceae, while Xanthopyrenia was commonly treated as a synonym of Arthopyrenia (and, more recently, of Pyrenocollema).[3]
André Aptroot treated Xanthopyreniaceae as a lichen-forming lineage of pyrenocarpous ascomycetes placed within Pyrenulales, alongside Pyrenulaceae. In his scheme, pyrenocarpous lichens are concentrated in a few coherent lineages rather than scattered across unrelated groups. Drawing on morphology, he regarded the characters used to split the old broadly defined Arthopyrenia into multiple families and even orders, especially differences in the hamathecium, as insufficient for such wide separation, and he retained these taxa in one order (Pyrenulales) and two families. He further noted that Pyrenulales typically have dark, carbonised (blackened) fruit-body walls of intricately interwoven cells (contrasting with the large, angular-celled walls typical of many Pleosporales), a practical feature that helps explain why Xanthopyreniaceae fits best within Pyrenulales. Earlier schemes had placed related families in Pleosporales or even Dothideales, and his comparison tables summarised these competing placements while emphasising that higher-order relationships remained unsettled given the limited and sometimes contradictory molecular data then available.[4]
Later multi-locus phylogenies (nuLSU, nuSSU, mtSSU, rpb1, rpb2, tef1-α) sampling Collemopsidium and Zwackhiomyces positioned Xanthopyreniaceae within the Dothideomyceta, but left its affinity to Dothideomycetes versus Arthoniomycetes unresolved. On that basis, Pérez-Ortega and colleagues erected the order Collemopsidiales to accommodate the family (including Collemopsidium and the lichenicolous Zwackhiomyces), estimated a Triassic crown age of roughly 230 Ma for the clade, and reported that marine Collemopsidium as currently delimited is likely paraphyletic with substantially underestimated species diversity.[5]
