LICHENICOLOUS SPECIES OF ARTHONIA ON LOBARIACEAE WITH NOTES ON EXCLUDED TAXA

The species of Arthonia s. lat. (Arthoniales, Ascomycotina) lichenicol ous on species of Pseudocyphellaria and other Lobariaceae are revised. Thirteen species are accepted, and eight species are described as new (all from the Southern Hemisphere): Arthonia badia Wedin & Hafellner, A. coriifoliae Wedin & Hafellner, A. flavicantis Wedin & Hafellner, A . maculiformis Wedin & Hafellner, A. minuta Wedin & Hafellner, A. sant essoniana Wedin & Hafellner, 'A.' semi-immersa Wedin & Hafellner, and A. subaggregata Wedin & Hafellner. Comparative notes on additional acc epted species previously described from Pseudocyphellaria or other Lob ariaceae (A. pelvetii, A. plectocarpoides, A. pseudocyphellariae, A. s tictaria, and A. subconveniens) are included, and a key to the Arthoni a (and similar) species growing on Lobariaceae is presented. The coelo mycete genus Subhysteropycnis Wedin & Hafellner is described for the s pecies S. maculiformans Wedin & Hafellner, the macroconidal anamorph o f Arthania badia. The lecanoralean genus Corticiruptor Wedin & Hafelln er is described as new to accommodate the single lichenicolous species C. abeloneae (P. M. Jorg.) Wedin & Hafellner comb. nov., and the addi tional new combination Plectocarpon linitae (R. Sant.) Wedin & Hafelln er is proposed. The names Celidium pelvetii Hepp, Sticta aurata b abor tiva Schaer. and Arthonia stictaria NyL are lectotypified, and the typ ifications are discussed. (C) 1998 The British Lichen Society.