Three families of pyrenocarpous lichens, the Porinaceae, Pyrenulaceae and Verrucariaceae, together comprise at least 10 per cent of all lichenized fungi and variously contribute in a significant way to lichen communities on all substrata and under all climatic conditions. The almost exclusively corticolous Pyrenulaceae, with more than 429 species in 16 genera, are especially numerous and abundant in subtropical and tropical regions while making a far more modest contribution to lichen diversity in cool-temperate and boreal latitudes. By contrast most Verrucariaceae (711 species in 37 genera) are saxicolous in temperate and cooler regions, as well as under hot-arid and subarid conditions. Conversely, diversity of Verrucariaceae is markedly reduced at low latitudes. Three genera, Polycornum, Porina and Trichothelium, and 394 species and infra- specific taxa are recognized in the pyrenocarpous lichen family Porinaceae (Ascomycota; Trichotheliales). The family is known from 150 countries and island territories, and it is especially diverse in the tropics and subtropics. This contribution gives publication details of accepted along with full synonymy. A country-based distribution is included for each species together with relevant literature sources. More than 700 synonyms are also listed separately, as are excluded taxa and doubtful species that are probably referrable to other families. A selection of distribution maps is provided, and patterns of known and likely diversity are discussed. The new combination Porina biroi (Szatala) P. M. McCarthy is made for Clathroporina biroi Szatala. Porina coarctata P. M. McCarthy & Harada nom. nov. replaces the illegitimate Porina aggregata P. M. McCarthy & Harada, and Porina peregrina Tretiach & P. M. McCarthy is validated.