title: The genus Theissenia: T. pyrenocrata, T. cinerea sp. nov., and T. eurima sp. nov.
abstract: The diagnosis of Theissenia is emended to include taxa that lack a definite central perithecial columella and taxa that feature ascospores with a germ slit. Theissenia cinerea is described as a new species that lacks a perithecial columella; T. eurima is described as a new species with ascospores having a germ slit. The type species, T. pyrenocrata, is redescribed and compared with the new species. The taxonomic position of Theissenia is discussed.
authors.affiliation: Institute of Botany, Academia Sinica, Nankang, Taipei 115, Taiwan.
authors.forename: Yu-Ming
authors.initials: YM
authors.lastname: Ju
authors.forename: Jack D
authors.initials: JD
authors.lastname: Rogers
authors.forename: Huei-Mei
authors.initials: HM
authors.lastname: Hsieh