Eopyrenula
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| Eopyrenula | |
|---|---|
 | |
| Eopyrenula leucoplaca | |
Scientific classification  | |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Dothideomycetes |
| Order: | Pleosporales |
| Family: | Dacampiaceae |
| Genus: | Eopyrenula R.C.Harris (1973) |
| Type species | |
| Eopyrenula leucoplaca (Wallr.) R.C.Harris (1973) | |
| Species | |
|
E. avellanae | |
Eopyrenula is a genus of lichen-forming fungi in the family Dacampiaceae.[1] It comprises six species.[2] The genus was established in 1973 by Richard C. Harris to separate these lichens from the related genus Pyrenula, based on differences in their reproductive structures and spore characteristics. Eopyrenula species are found on tree bark in temperate regions, particularly in Europe and North America, where they form thin, pale grey crusts dotted with tiny dark fruiting bodies. The genus occupies an uncertain position in fungal classification, with its family placement remaining provisional pending molecular analysis. These inconspicuous lichens can be identified by their brown, multi-segmented ascospores and their association with the green alga Trentepohlia.
Eopyrenula was erected by Richard C. Harris (1973) as a new genus in the Pyrenulaceae to accommodate material long kept in Pyrenula, with the type species designated as Eopyrenula leucoplaca (based on Wallroth's Verrucaria leucoplaca of 1831). Harris separated the genus on structural grounds: unlike Pyrenula, Eopyrenula lacks a well-developed pseudostromatic involucrellum (the outer "shell" of the perithecium), its spores do not develop a thick endospore, and its pycnidia produce brown, transversely septate macroconidia (while still having the filiform, colourless microconidia seen in Pyrenula). He noted that these features make Eopyrenula morphologically intermediate between Pyrenula and the lichen-forming members of Arthopyrenia; superficially similar Blastodesmia was excluded because it lacks algae and differs in ascocarp and conidial characters.[3]
Within the genus, Harris treated a single species, E. leucoplaca. Earlier authors had conflated this taxon with Verrucaria farrea (Pyrenula farrea), but Edvard Vainio examined the type of V. farrea and concluded it was different, supporting the retention of leucoplaca as a distinct species under Eopyrenula. Harris also clarified that Bruce Fink's North American variety Pyrenula leucoplaca var. pluriloculata—proposed because some material showed more than three septa—was unnecessary, as European material is consistently 5–6-septate and North American material with 5–6 septa belongs here. He further showed that many North American specimens labeled "Pyrenula leucoplaca" or "P. farrea" actually represent a non-lichenised, Melanomma-like fungus confined to living bark of trembling aspen; that element can be told by its lack of iodine reaction and consistently 3-septate spores with a thick gelatinous sheath.[3]
Eopyrenula is presently treated in the family Dacampiaceae, but its placement is unsettled. Some authors have instead kept it as Pezizomycotina incertae sedis (uncertain placement),[4] a view followed in the "Revisions of British and Irish Lichens" treatment in 2023.[5] Morphologically it also shows clear affinities to Pyrenulaceae (Eurotiomycetes); given these conflicts, most authors regard its family-level position as provisional pending sequencing.[2][6]
