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The genus Melanconis (Melanconidaceae, Diaporthales) in the strict sense is here re-evaluated regarding phylogenetic structure, taxonomy, distribution and ecology. Using a matrix of sequences from ITS, LSU, ms204, rpb2, tef1 and tub2, eight species are recognised and their phylogenetic positions are determined. Based on phylogenetic, morphological and geographical differentiation, Melanconis marginalis is subdivided into four subspecies. Melanconis italica is reduced to a subspecies of Melanconis marginalis. The two species Melanconis larissae from Betula sp. and M. pacifica from Alnus rubra are described as new. Melanconis alni and M. stilbostoma are lectotypified and M. alni, M. marginalis and M. stilbostoma are epitypified. All GenBank sequences deposited as Melanconis alni are shown to actually represent M. marginalis and those as M. marginalis belong to the newly described M. pacifica. Currently, Alnus and Betula are the sole host genera of Melanconis. All species and subspecies are (re-)described and illustrated. In addition, the neotypification of Melanconium pterocaryae is here validated.

Melanconis-like fungi are distributed in several families of Diaporthales, mainly Juglanconidaceae, Melanconidaceae, Melanconiellaceae and Pseudomelanconidaceae. A new Melanconis-like genus of Pseudomelanconidaceae was discovered on branches of Chinese chestnut (Castanea mollissima) in southern China, which was confirmed by both morphology and phylogenetic analysis of combined ITS, LSU, tef1a and rpb2 sequences. The new genus Micromelanconis is characterized by two types of conidia from natural substrate and manual media of PDA, respectively. Conidia from Chinese chestnut branches are pale brown, ellipsoid, multiguttulate, aseptate with hyaline sheath. While conidia from PDA plates are pale brown, long dumbbell-shaped, narrow at the middle and wide at both ends, multiguttulate, aseptate, and also with hyaline sheath. All Pseudomelanconidaceae species were only reported on tree branches in China until now. More interesting taxa may be discovered if detailed surveys on tree-inhabiting fungi are carried out in East Asia in the future.

Diaporthalesis an important ascomycetous order comprising phytopathogenic, saprobic, and endophytic fungi, but interfamilial taxonomic relationships are still ambiguous. Despite its cosmopolitan distribution and high diversity with distinctive morphologies, this order has received relativelyiaceae,Macrohilaceae,Melanconidaceae,Pseudoplagiostomaceae,Schizoparmaceae,StilbosporaceaeandSydowiellaceae. Taxonomic uncertainties among genera are also clarified and recurrent discrepancies in the taxonomic position of families within theDiaporthalesare discussed. An updated outline and key to families and genera of the order is presented.

The genus Melanconis (Melanconidaceae, Diaporthales) in the strict sense is here re-evaluated regarding phylogenetic structure, taxonomy, distribution and ecology. Using a matrix of sequences from ITS, LSU, ms204, rpb2, tef1 and tub2, eight species are recognised and their phylogenetic positions are determined. Based on phylogenetic, morphological and geographical differentiation, Melanconis marginalis is subdivided into four subspecies. Melanconis italica is reduced to a subspecies of Melanconis marginalis. The two species Melanconis larissae from Betula sp. and M. pacifica from Alnus rubra are described as new. Melanconis alni and M. stilbostoma are lectotypified and M. alni, M. marginalis and M. stilbostoma are epitypified. All GenBank sequences deposited as Melanconis alni are shown to actually represent M. marginalis and those as M. marginalis belong to the newly described M. pacifica. Currently, Alnus and Betula are the sole host genera of Melanconis. All species and subspecies are (re-)described and illustrated. In addition, the neotypification of Melanconium pterocaryae is here validated.

Diaporthales is a fungal order comprising important plant pathogens, saprobes and endophytes on a wide range of woody hosts. It is often difficult to differentiate the pathogens in this order, since both the morphology and disease symptoms are similar among the various species. In the current study, we obtained 15 representative diaporthalean isolates from six tree hosts belonging to plant families Betulaceae, Fagaceae, Juglandaceae, Rosaceae, and Ulmaceae from Mount Dongling in China. Six species were identified residing in four families of Diaporthales (Diaporthaceae, Erythrogloeaceae, Juglanconidaceae and Melanconidaceae). Based on morphological comparison and the phylogenetic analyses of partial ITS, LSU,cal,his3,rpb2,tef1-αandtub2gene sequences, we identified five known species (Diaporthe betulina,D. eres,D. rostrata,Juglamconis oblongaandMelanconis stilbostoma) and one novel species (Dendrostoma donglinensis). These results represent the first study of diaporthalean fungi associated with canker and dieback symptoms from Mount Dongling in Beijing, China.

Melanconis-like species comprise latent fungal pathogens with a wide range of woody hosts. Taxonomy of these pathogens is difficult due to their uninformative descriptions and similar asexual morphology. Based on molecular phylogenies, many species of this group were placed in various families of Diaporthales. In this study, eight species of melanconis-like fungi were isolated from Betulaalbosinensis, B.platyphylla (Betulaceae), Cornuscontroversa (Cornaceae), Corylusmandshurica (Betulaceae) and Juglansregia (Juglandaceae) in China. These species were phylogenetically placed in three families of Diaporhthales, i.e. Juglanconisjuglandina, J.oblonga (Juglanconidaceae), Melanconiellabetulicolasp. nov., M.corylinasp. nov. (Melanconiellaceae), Melanconisbetulae, Ms.itoana, Ms.stilbostoma (Melanconidaceae) and one new genus, Sheathospora (Melanconiellaceae). Sheathospora is proposed to accommodate Melanconiellacornuta with conical and discrete pycnidia with aseptate, hyaline, cylindrical to ellipsoidal conidia with distinct hyaline sheath on branches of Cornuscontroversa. Combined analyses of ITS, LSU, CAL, RPB2 and TEF1-α sequence data were used to construct the molecular phylogeny. Additionally, we provided separate phylogenetic trees for three families (Juglanconidaceae, Melanconidaceae and Melanconiellaceae) to show the species distribution of melanconis-like fungi in China.

In this study we accept 25 families in Diaporthales based on phylogenetic analyses using partial ITS, LSU, rpb2 and tef1-α gene sequences. Four different families associated with canker and dieback of tree hosts are morphologically treated and phylogenetically compared. These include three new families (Diaporthostomata-ceae, Pseudomelanconidaceae, Synnemasporellaceae), and one new genus, Dendrostoma (Erythrogloeaceae). Dendrostoma is newly described from Malus spectabilis, Osmanthus fragrans and Quercus acutissima having fusoid to cylindrical, bicellular ascospores, with three new species namely D. mali, D. osmanthi and D. quercinum. Diaporthostomataceae is characterised by conical and discrete perithecia with bicellular, fusoid ascospores on branches of Machilus leptophylla. Pseudomelanconidaceae is defined by conidiogenous cells with apical collarets and discreet annellations, and the inconspicuous hyaline conidial sheath when mature on Carya cathayensis, compared to morphologically similar families Melanconidaceae and Juglanconidaceae. Synnemasporellaceae is proposed to accommodate fungi with synnematous conidiomata, with descriptions of S. toxicodendri on Toxico-dendron sylvestre and S. aculeans on Rhus copallina.

56. Titania [Titania] Meigen, 1800: 35. CURRENT STATUS: Name suppressed for the purposes of the Principle of Priority but not the Principle of Homonymy by action of I.C.Z.N. (1955a: 421 [Opinion 348]; treated under Chlorops Meigen, 1803 [teste Sabrosky (1999: 308)]. FAMILY: CHLOROPIDAE. REMARKS: Titania Meigen (1800: 35) was declared an available name by two actions of the ICZN Commission (I.C.Z.N. 1910: 66 [Opinion 28], 1944: 181 [Opinion 152]). Later, in order to protect the younger name Chlorops Meigen, 1803, the ICZN Commission (I.C.Z.N. 1955a: 421 [Opinion 348]) ruled to suppress Titania Meigen, 1800 for the purposes of the Principle of Priority but not for the Principle of Homonymy; treated under Chlorops Meigen, 1803 [teste Nartshuk (2012: 26)]. Titania Meigen in Hendel, 1908: 63 . ORIGINALLY INCLUDED SPECIES: None. FIRST INCLUDED SPECIES: Chlorops laeta Meigen, 1803 (in Coquillett 1910a: 615). TYPE SPECIES: Chlorops laeta Meigen, 1803, by subsequent designation (Coquillett 1910a: 615). CURRENT STATUS: Preoccupied by Titania Meigen, 1800; junior synonym of Chlorops Meigen, 1803. New Synonymy. REMARKS: Titania was originally proposed by Meigen (1800: 35) without included species, the entire work of which was subsequently suppressed for the purposes of zoological nomenclature by action of the I.C.Z.N. (1963: 339 [Opinion 678]). Hendel (1908: 63) was the first after Meigen (1800) to give characters to differentiate the taxon (reproducing Meigen’s characters) and to treat Titania as valid, which makes the name available from that work with Meigen as author. No species were included in Hendel (1908). The first included species is in Coquillett (1910a: 615), who designated Chlorops laeta Meigen, 1803 as the type species. The action of the I.C.Z.N. (1955a: 421 (Opinion 348) suppressed Titania only for the purpose of priority and not for homonymy. As there is no wording in Opinion 678 to contravene earlier rulings of names in Meigen (1800), this allows for Titania to be made available by subsequent usage as a valid taxon, but the name immediately becomes invalid as a junior homonym of Titania Meigen, 1800.

Melanconis is a monotypic genus in Melanconidaceae and mostly restricted to hardwood trees in Betulaceae, as endophytes and plant pathogens. During a routine forest pathogens investigation of canker disease in China, some melanconidaceous fungi were observed on Betula spp. with various symptoms. The primary objective of the present study was to identify species of Melanconidaceae associated with canker and dieback of Betula spp. in China. In the present study, we investigated 45 isolates using morphology and multi-gene phylogenetic analyses based on the internal transcribed spacers (ITS), nuclear large subunit rDNA (LSU), RNA polymerase II subunit 2 (rpb2), translation elongation factor 1-α (tef1-α) and β-tubulin (tub). Three melanconidaceous taxa were identified: Melanconis betulae sp. nov., M. itoana and M. stilbostoma. This is the first phylogenetic study evaluating species of Melanconis associated with canker and dieback disease of Betula spp. in China, resulting in the description of a novel species and the report of M. itoana as a new record.

Members of Melanconiella are opportunistic pathogens and endophytic fungi, and have been found to confined so far, on the collection of host family Betulaceae. Moreover, two fresh specimens associated with canker and dieback of Cornus controversa and Juglans regia collected in Shaanxi, China were found as distinct and new species of Melanconiella, based on morphological and multi-gene, combined, phylogenetic analyses (ITS, LSU, rpb2 and tef1-α). Results also revealed the host and geographic range extensions of this genus. Melanconiella cornuta sp. nov. is introduced with an illustrated account and differs from similar species in its host association and multigene phylogeny.