- Source: Dirina cretacea
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 as a member of the genus Chiodecton. The type specimen was collected in Croatia. Anders Tehler transferred it to the genus Dirina in 1983. The lichen has a whitish-grey thallus (0.3–1.0 mm thick) lacking soralia, and a chalk-like medulla. Its ascomata have a circular outline and a diameter of up to 3.8 mm; the apothecial disc is also white grey with a layer of pruina, and is surrounded by a thalline margin. Ascospores measure 19–23 by 5–6 μm.
