Labyrintha Malcolm, Elix & Owe-Larss.
Type : Labyrintha implexa Malcolm, Elix & Owe-Larsson
Description : Thallus crustose, closely attached, areolate, on a black, prothallus, cephalodiate. Photobiont green, trebouxioid, arranged in vertical sheets. Cephalodia cyanobacterial, Gloeocapsa. Ascomata apothecia, immersed, immarginate, appearing aspicilioid. Hamathecium of branched, anastomosing paraphyses. Hymenium I+ blue. Asci Porpidia -type (Malcolm & Galloway 1997: 187), 8-spored. Ascospores simple, broadly ellipsoidal, hyaline, halonate when young, becoming greenish black at maturity. Conidiomata pycnidia, immersed. Conidia short, fusiform.
Labyrintha is an endemic, monospecific genus in the family Porpidiaceae (Eriksson et al. 2004; Pennycook & Galloway 2004; Eriksson 2005), found on acidic alpine rocks and characterised by: a green photobiont arranged in vertical sheets; cephalodia containing Gloeocapsa; immersed ±aspicilioid apothecia; asci Porpidia -type; large, simple, halonate ascospores (greenish black at maturity); fusiform conidia; and no secondary chemistry. The particular arrangement of the photobiont (in vertical sheets) distinguishes it from taxa in Amygdalaria (Brodo & Hertel 1987). It is discussed in Malcolm (1995) and Malcolm et al. (1995a).
