Published online by Cambridge University Press: 28 March 2007
The new generic names Metamelanea Henssen and Strotnatella Henssen are described inthe Lichinaceae. They are denned by the developmental morphology of the ascocarp and thallus structure. In both genera the thallus is subfruticose, and the cyanobiont a single-celled member of the Chroococcales. The genus Metamelanea is based on the type species M.umbonata Henssen, newly described from the Alps, and M. melambola (Tuck.) Henssen comb, nov., found in North America. The genus Strotnatella is based on the single species, S. bermudana (Riddle) Henssen, formerly Psorotichia bermudana Riddle. The new genera are compared with species of other genera of the Lichinaceae: Gyrocollema, Lecidopyrenopsis and Porocyphus; some micrographs of Lecidopyrenopsis corticola Vainio. are also included. The new combination Porocyphus ocellatus(Th. Fr.) Henssen is made; Pyrenopsis triptococcus Nyl. is selected as lectotype of Pyrenopsis subgen. Cladopsis Nyl. (syn. Cladopsis (Nyl) Hue).