Fuscidea
From Wikipedia, the free encyclopedia
| Fuscidea | |
|---|---|
 | |
| Fuscidea cyathoides | |
Scientific classification  | |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Umbilicariales |
| Family: | Fuscideaceae |
| Genus: | Fuscidea V.Wirth & Vèzda (1972) |
| Type species | |
| Fuscidea aggregatilis (Grummann) V.Wirth & Vězda (1972) | |
| Synonyms[1] | |
| |
Fuscidea is a genus of crustose lichens in the family Fuscideaceae. It has about 40 species.[2] The genus was established in 1972 by Volkmar Wirth and Antonín Vězda, with its name derived from the Latin for 'brown', referring to the typical colouration of these lichens. Species of Fuscidea grow almost exclusively on acidic, silica-rich rocks, favouring steep faces in humid, high-rainfall regions such as Atlantic coastlines and mountain ranges. They form cracked or patchy crusts that spread over a characteristically dark underlying margin, often creating mosaic-like patterns where neighbouring colonies meet.
Fuscidea was circumscribed in 1972 by the lichenologists Volkmar Wirth and Antonín Vězda as part of their revision of the Lecidea cyathoides (= rivulosa) group, which they regarded as an isolated and coherent assemblage within the then broadly defined genus Lecidea. They argued that some species of this group had been misplaced in Microlecia, because Choisy's concept of that genus also included unrelated Catillaria species, and they therefore restricted Microlecia to the Catillaria-like taxa with Microlecia lenticularis as its type. To accommodate the Lecidea cyathoides group they established Fuscidea, designating Fuscidea aggregata (based on Lecidea contigua var. rivulosa β aggregata Flotow) as the type species, and they provided new combinations for fifteen species previously placed in Lecidea. Wirth had already introduced the name earlier the same year in a study of siliceous rock lichen communities, but without designating a type species, so the diagnosis and combinations were republished in their joint paper.[3]
In the protologue Wirth and Vězda characterised Fuscidea as a group of crustose lichens with brown to dark brown apothecia, a pale hymenium and hypothecium, a brown proper exciple, paraphyses with pigmented apices, and spores that may become brownish and sometimes 1-septate with age. They also stressed the presence of brown, crateriform pycnidia with very short conidia, and a dark marginal line to the thallus, and regarded Fuscidea as closely related to Buellia species with thin-walled spores. The species were described as strongly acidophilous lichens of siliceous rock, avoiding calcareous and other base-rich substrates, and occurring mainly on steep rock faces in humid, high-rainfall regions, particularly in Atlantic areas and mountain ranges; only a single species was known from bark. The generic name is derived from the Latin fuscus ('brown'), referring to the frequent brownish coloration of the thallus and apothecia.[3]
