title: A re-appraisal of Harknessia (Diaporthales), and the introduction of Harknessiaceae fam. nov.
abstract: Harknessiaceae is introduced as a new family in the ascomycete order Diaporthales to accommodate species of Harknessia with their Wuestneia-like teleomorphs. The family is distinguished by having pycnidial conidiomata with brown, furfuraceous margins, brown conidia with hyaline, tube-like basal appendages, longitudinal striations, and rhexolytic secession. Six species occurring on Eucalyptus are newly introduced, namely H. australiensis, H. ellipsoidea, H. pseudohawaiiensis, and H. ravenstreetina from Australia, H. kleinzeeina from South Africa, and H. viterboensis from Italy. Epitypes are designated for H. spermatoidea and H. weresubiae, both also occurring on Eucalyptus. Members of Harknessia are commonly associated with leaf spots, but also occur as saprobes and endophytes in leaves and twigs of various angiosperm hosts.
authors.affiliation: CBS Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands; ;  Microbiology, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands. ;  Wageningen University and Research Centre (WUR), Laboratory of Phytopathology, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
authors.forename: P W
authors.initials: PW
authors.lastname: Crous
authors.forename: B A
authors.initials: BA
authors.lastname: Summerell
authors.forename: R G
authors.initials: RG
authors.lastname: Shivas
authors.forename: A J
authors.initials: AJ
authors.lastname: Carnegie
authors.forename: J Z
authors.initials: JZ
authors.lastname: Groenewald
keywords: Harknessiaceae; ITS; LSU; biodiversity; fungal pathogens; phylogeny; systematics