Peltula Nyl.
Thallus areolate, squamulose, peltate or subfruticose, attached by a small area of rhizines or an umbilicus, dorsiventral, heteromerous, terricolous or saxicolous. Upper and lower surfaces corticate, with or without soredia. Medulla white, loosely woven. Photobiont blue-green, Anacystis. Apothecia immersed. Asci with a gelatinous sheath, with 16-100 or more spores. Ascospores colourless, simple. Pycnidia immersed. Conidia fusiform.
Peltula is a cosmopolitan genus of c. 18 species included in the family Heppiaceae. It is characteristic of arid and semi-arid regions and found either on rocks or soil [Wetmore Ann. Mo. bot. Gdn 57: 158-209 (1970); Swinscow and Krog Norw. J. Bot. 26: 213-224 (1979); Filson and Rogers "Lichens of South Australia": 142-143 (1979)]. One species is recorded from New Zealand but the genus has not been widely collected or studied here.
