Microfungi in the phyllosphere of <i>Senecio umbrosus</i> Waldst. et Kit., a host species with a narrow ecological niche

Among the biotic factors that limit plant growth, population size, and reproduction, there is a mass appearance of microscopic parasitic fungi. The aim study was to determine spectrum microfungi degree leaf surface infection in ragwort <i>Senecio umbrosus</i>, i.e., one Polish red data book species. In 2014–2016, studies on diversity dynamics were carried out within its White Mt, southeastern Poland, where it grows xerothermic habitats. During three seasons (6 collection series between May October), 15 microfungal species identified total (1–9 per date, 9 each season). Only <i>Coleosporium tussilaginis</i> present all dates, accounted for 30–100% records microfungi. Three hyperparasites also <i>C. tussilaginis</i>: <i>Cladosporium uredinicola, Ramularia coleosporii</i>, <i>Alternaria</i> sp. other taxa found five (<i>Boeremia exigua, Leptosphaeria ogilviensis</i>), four (<i>Alternaria</i> sp.), or times (<i>Ascochyta compositarum, Periconia cookei</i>), but majority noted twice only once, depending meteorological conditions given growing season. common microfungi, we collected <i>Ascochyta compositarum</i>, which new Poland. Additionally, fungus/host combinations tussilaginis</i>.