''Dirina cretacea'' is a species of saxicolous (rock-dwelling), crustose lichen in the family Roccellaceae. Its distribution is largely in the eastern Mediterranean, and in Andalusia, Spain. It was formally described as a new species in 1899 by

Alexander Zahlbruckner Alexander Zahlbruckner (31 May 1860, Svätý Jur – 1938, Vienna) was an Austrian- Hungarian botanist who specialized in the study of lichens. Johann Babtist Zahlbruckner, an earlier Austrian botanist, was his grandfather. From 1878 to 1883 ...

as a member of the genus ''

Chiodecton ''Chiodecton'' is a genus of lichens in the family Roccellaceae. The genus was circumscribed by lichenologist Erik Acharius in 1814, with '' Chiodecton sphaerale'' assigned as the type species. Species , Species Fungorum accepts 22 species in '' ...

''. The type specimen was collected in Croatia. Anders Tehler transferred it to the genus ''

Dirina ''Dirina'' is a genus of lichen-forming fungi in the family Roccellaceae. All ''Dirina'' species are crustose lichens with a whitish to greyish brown thallus, and live either on rock or on bark–some species can live on both. The partner is ...

'' in 1983. The lichen has a whitish-grey thallus (0.3–1.0 mm thick) lacking

soralia Soredia are common reproductive structures of lichens. Lichens reproduce asexually by employing simple fragmentation and production of soredia and isidia. Soredia are powdery propagules composed of fungal hyphae wrapped around cyanobacteria o ...

, and a chalk-like medulla. Its ascomata have a circular outline and a diameter of up to 3.8 mm; the apothecial is also white grey with a layer of , and is surrounded by a . Ascospores measure 19–23 by 5–6

μm The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

References

cretacea Lichen species Lichens described in 1899 Lichens of Southeastern Europe Lichens of Southwestern Europe Lichens of North Africa Taxa named by Alexander Zahlbruckner {{Arthoniomycetes-stub