Abstract
Podosphaera filipendulensis, a new teleomorph of powdery mildew was discovered on living leaves of Filipendula vestita (Rosaceae). It is the first species of powdery mildew that causes wilting and ultimately death of apical infected leaves of F. vestita. It is described, illustrated and compared with other Podosphaera species reported on Rosaceae and a key to all species reported on Rosaceae is provided. The phylogeny of this species has been inferred from internal transcribed spacer (ITS) rDNA sequence data. Phylogenetically, P. filipendulensis is close to P. ferruginea var. ferruginea and P. macularis but differs in having larger chasmothecia, smaller peridium cells, shorter, narrower and aseptate appendages, 8-spored asci and smaller ascospores.