This issue of Mycological Research News features: Cause of the Irish potato famine finally identified; A lichen theme; Other papers in this issue; and Pathogen introduction as a collateral effect of military activity.

The fast-tracked lead paper in this part reports the identity of the Phytophthora infestans halpotype responsible for the Irish potato famine in the 1840s.

Seven papers are collected together to make this a Lichen Theme issue. These address mating systems in Xanthoria; secondary compound production in culture in Ramalina spp.; the molecular phylogeny of Physconia spp. and the Lecanora rupicola group; molecular, morphological and ecological variation and systematics in marine Collemopsidium spp.; a revision of non-yellow Rhizocarpon spp. in Nordic countries; and new corticolous Trichothelium spp.

Other papers show that the generic name Verticillium has been misapplied and take action to maintain its current use; examine the survival of chytrid spores in stressful soils; and compare the seasonality of a Laboulbenia and its beetle host.

The following new scientific names are introduced in this part: Trichothelium angustisporum, T. caudatum, and T. kalbii spp. nov.; Acrostalagmus luteo-albus (syn. Sporotrichum luteo-album), Collemopsidium foveolatum (syn. Arthopyrenia foveolata), and C. ostrearum (syn. Lecanactis ostrearum) combs. nov.; and Lecanora rouxii (syn. Lepraria flavescens) nom. nov.