Gyalideopsis Vězda
Thallus crustose, thin, often filmy, smooth or rarely ± verrucose, effuse. Photobiont green ? Trebouxia. Ascocarps orbicular, red-brown to black, ± pellucid when wet, with a persistent, often slightly raised, proper margin, thalline margin absent. Excipulum proprium and thecium characteristically composed of a continuous, loose network of anastomosing paraphysoids in a common gelatinous matrix. Asci cylindrical-clavate to ovate, apices markedly thickened, 2- to 8-spored. Ascospores colourless, transversely septate to densely muriform. Pycnidia unknown.
Gyalideopsis is characterised by the following: (1) an excipulum which lacks any secondary differentiation into a parathecium and amphithecium and which is entirely composed of slender, anastomosing and ramifying hyphae; (2) a non amyloid hymenium; (3) a conspicuous gelatinous hymenial matrix through which the thin paraphysoids anastomose and ramify as in the adjacent excipulum; (4) asci with an apical apparatus in the form of a nasse; (5) hyaline spores which are either transversely septate or muriform, the individual cells of which are ± constricted at their junction with adjacent cells; (6) a chlorococcoid photobiont.
It superficially resembles Gyalidea from which it may be readily distinguished by the delicate paraphysoidal network in place of the simple true paraphyses of that genus. Gyalideopsis is most closely allied to Tricharia and Calenia and is included with them in the family Asterothyriaceae [Vĕzda Folia geobot. phytotax. 7: 203-215 (1972)]. Five species are known [Vĕzda, loc. cit. ; James Lichenologist 7: 155-161 (1975)]. One species, possibly new, is known from New Zealand.
