Flora of New Zealand Series

Type : Mazosia rotula (Mont.) A.Massal. [=Strigula rotula Mont.]

Description : Thallus custose, effuse, or finely warted, ecorticate, rarely (one species, M. sorediifera) sorediate; without a marginal prothallus. Photobiont green, Phycopeltis. Ascomata apothecia, rounded, their bases immersed. Exciple tissue thin, but distinct, dark, formed of ±radiate hyphae. Hymenium I+ orange to red, K/I± blue. Asci fissitunicate, clavate, ±thick-walled, of Opegrapha -type, ascus wall I+ blue, and two I+ dark-blue transverse bands in ocular region (Erkisson & Hawksworth 1995: 58). Ascospores septate, fusiform or acicular, microcephalic, colourless. Conidiomata pycnidia, immersed. Upper wall dark-brown, basal wall colourless or pale-brown. Conidiophores simple. Conidia formed apically; macroconidia simple, oblong to cylindrical; microconidia simple, ellipsoidal to fusiform – both types in the same pycnidium or in separate pycnidia.

Mazosia, a tropical genus of mainly foliicolous taxa as well as species colonising bamboo culms, is included in the family Roccellaceae (Eriksson et al. 2004; Pennycook & Galloway 2004; Eriksson 2005). The general appearance of species of Mazosia having immersed, rounded, black ascomata is very characteristic, as is the anatomy of the hymenium and the shape of the ascospores, being similar to Opegrapha (Lücking 1992). Santesson (1952) discussed nine species from a wide variety of tropical habitats. Two additional species were described by Kalb & Vězda (1988a), a further three new species were described from Australia (Lumbsch & Vězda 1990; Sipman 1991a; Kalb & Vězda 1994b) and three new species from Costa Rica were described by Lücking & Matzer (1996). Farkas & Sipman (1997) list 16 taxa (14 species and two subspecies). Matzer (1996: 55–56) presents useful notes on the genus and described a new species lichenicolous on another species of Mazosia. Presently 17 species and two subspecies are known worldwide of which two are recorded from New Zealand (Bartlett 1988; Galloway 1992b; Malcolm & Galloway 1997).