Dirina Fr.,
Type : Dirina ceratoniae Fr.
Description : Thallus crustose, effuse, continuous to cracked, verruculose, to areolate or bullate, cream-white, grey-white, pale greenish, buff-brown, grey-brown to dark-grey with or without pruina, with or without soralia, often delimited by a black prothallus when contiguous with other lichens. Cortex of anticlinally arranged hyphae. Photobiont green, Trentepohlia (fresh material scratching orange). Medulla thick, cretaceous, white. Ascomata apothecia, sometimes stromatoid, sessile, substipitate to immersed and appearing lirellate, disc grey-white to dark-grey or pale- to dark-brown, pruinose. Thalline margin entire when young, undulating or stringly undulating at maturity. Proper margin a thin parathecium. Epithecium brownish, with intertwined and branched paraphysoids. Hymenium hyaline, 50–140 μm tall. Hamathecium of paraphysoids, slender, parallel, sparsely branched, septate, 1–3 μm diam., often with incorporated crystals. Hypothecium dark-brown, or hyaline, sharply defined from white medulla. Asci cylindrical, 70–120 × 11.5–18 μm, 8-spored. Ascospores colourless fusiform, curved, 3-septate, walls smooth. Conidiomata pycnidia, solitary, immersed, red-brown to dark-brown. Conidia filiform, curved or sickle-shaped, 10–16 × 1 μm.
Dirina, placed in the family Roccellaceae (Eriksson et al. 2004; Pennycook & Galloway 2004; Eriksson 2005), is a rather small genus of c. 12 known species (Tehler 1983, 2002; Tehler et al. 1995; Sparrius 2004), of which one occurs on coastal rocks in southern New Zealand, being one of two known Southern Hemisphere species of a predominantly Northern Hemisphere genus (Sparrius 2004).
