Resolving Tiarosporella spp. allied to Botryosphaeriaceae and Phacidiaceae Author Crous, Pedro W. CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands; & Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa & Microbiology, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands Author Müller, Michael M. Natural Resources Institute Finland (LUKE), P. O. Box 18, FIN- 01301 Vantaa, Finland Author Sánchez, Romina M. Centro de Recursos Naturales Renovables de la Zona Semiárida-Universidad Nacional del Sur Camino La Carrindanga Km 7, B 8000 FWB, Bahía Blanca, Argentina Author Giordano, Lucrecia Centro de Recursos Naturales Renovables de la Zona Semiárida-Universidad Nacional del Sur Camino La Carrindanga Km 7, B 8000 FWB, Bahía Blanca, Argentina Author Bianchinotti, M. Virginia Centro de Recursos Naturales Renovables de la Zona Semiárida-Universidad Nacional del Sur Camino La Carrindanga Km 7, B 8000 FWB, Bahía Blanca, Argentina Author Anderson, Freda E. Centro de Recursos Naturales Renovables de la Zona Semiárida-Universidad Nacional del Sur Camino La Carrindanga Km 7, B 8000 FWB, Bahía Blanca, Argentina Author Groenewald, Johannes Z. CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands; text Phytotaxa 2015 2015-03-12 202 2 73 93 http://dx.doi.org/10.11646/phytotaxa.202.2.1 journal article 10.11646/phytotaxa.202.2.1 1179-3163 13641335 Mucoharknessia Crous, R.M. Sánchez & Bianchin. , gen. nov. MycoBank MB811254 Etymology:— Muco , derived from the mucoid appendage, and Harknessia (resembling the genus). Mucoharknessia resembles Harknessia ( Harknessiaceae , Diaporthales ), but is distinguished from that genus by having pycnidia that lack furfuraceous tissue surrounding its ostiole, and conidia that have a mucoid apical appendage. Foliicolous . Conidiomata immersed, separate or aggregated, pycnidial, unilocular, globose to subglobose, blackish on leaves; ostiole subepidermal, circular to subcircular, opening onto the abaxial side of leaves by means of a longitudinal split in epidermis. Peridium arranged in two layers, the external stromatic, with brown cells of textura angularis ; the internal conformed by flattened, hyaline cells, 10–15 μm thick. Conidiophores reduced to conidiogenous cells, lining the conidiomatal cavity. Conidiogenous cells lageniform to subcylindrical, smooth, covered in mucus, hyaline; proliferating several times percurrently at apex, with flared collarette visible. Conidia oval to ellipsoidal, appendaged, thick-walled, smooth to finely verruculose, lacking striations, brown; apical appendage extracellular ( Type B , sensu Nag Raj 1993 ), mucilaginous, irregular, smooth, hyaline ; basal appendage tubular, thin walled, smooth, hyaline, often collapsing. Microconidia not seen. Type species:— Mucoharknessia cortaderiae Crous, R.M. Sánchez & Bianchin.