Abstract
Chlorociboria, a commonly reported saprobic genus in Chlorociboriaceae, is characterized by discoid, blue-green, olivaceous, yellow or white apothecia, filiform or thin-clavate paraphyses, cylindric-clavate asci, and ascospores that are elliptic to fusiform, or allantoid, hyaline. According to our morphological and phylogenetic studies of nine Chlorociboria collections from southwest China, four new species (C. ailaoense, C. bannaensis, C. laojunense and C. yulongense) are proposed. Chlorociboria ailaoense is identified by its blue to dark blue-green receptacles without tomentum hyphae, along with medially and basally branched paraphyses, and fusiform ascospores. Chlorociboria bannaensis is recognized by light blue receptacles lacking tomentum hyphae, black stipes, a degenerated medullary excipulum, thin-clavate, unbranched paraphyses, inamyloid asci, and ellipsoid ascospores. For C. laojunense, distinctive characters include light blue discs, dark blue-green flanks without tomentum hyphae, asci without croziers, and fusiform ascospores. Chlorociboria yulongense is characterized by olive green to dark discs, white flanks without tomentum hyphae, filiform, branched paraphyses, inamyloid asci, and elliptic to allantoid ascospores. Our phylogenetic analyses, based on the internal transcribed spacer (ITS) and the nuclear ribosomal large subunit (LSU) data of Chlorociboriaceae, strongly support the establishment of the four new species. In addition, we have provided an updated key to distinguish species of Chlorociboria.