Hypoxylon Species Research Articles

New Hypoxylon species and notes on some names associated with or related to Hypoxylon

These new species of Hypoxylon are described: H. elevatidiscus, H. squamulosum, H. subalbum and H. vinosopulvinatum. A referenced list of all Hypoxylon species known to us described since 1996 is given and a key presented. Names associated with Hypoxylon that were not given in the Ju and Rogers monograph are annotated and diagnostic corrections of taxa discussed in that monograph are given.

Macrocarpones, novel metabolites from stromata of Hypoxylon macrocarpum, and new evidence on the chemotaxonomy of Hypoxylon species

Several species of the genus Hypoxylon (Xylariaceae) were studied for morphological characters and HPLC-based secondary metabolite profiles. It was confirmed that Hypoxylon is divided into two groups of species, containing either Mitorubrin type azaphilones or binaphthyls, respectively, as main metabolites. In Hypoxylon species of the latter group, some metabolites that are known from the allied genus Daldinia (i.e., Daldinal A in H. fuscum and Daldinin C in H. fuscopurpureum), were encountered for the first time. Moreover, three novel aromatic polyketides, for which the trivial names Macrocarpones A, B and C are proposed, were isolated from ascostromata of Hypoxylon macrocarpum and identified by high resolution mass spectrometry and 2D-NMR spectroscopy. Orsellinic Acid was also identified from ascostromata of H. howeianum and detected by HPLC-MS and HPLC-UV/Vis fingerprinting methodology in H. fragiforme and H. rubiginosum, but not in other examined Hypoxylon species. Due to these studies, H. fuscopurpureum sensu Y.-M. Ju & J.D. Rogers 1996 was identified as a new record for Germany.

New Hypoxylon Species from Papua New Guinea and Notes on Some Other Taxa

Hypoxylon duriloculatum, H. madangense, H. rugulosporum, and H. vandervekenii are described as new species. Two dichotomous keys to 31 Hypoxylon species of sections Hypoxylon and Annulata known to occur in Papua New Guinea are presented and a synoptic key is given to taxa of section Hypoxylon.

New Hypoxylon species from Papua New Guinea and notes on some other taxa

Hypoxylon duriloculatum, H. madangense, H. rugulosporum, and H. vandervekenii are described as new species. Two dichotomous keys to 31 Hypoxylon species of sections Hypoxylon and Annulata known to occur in Papua New Guinea are presented and a synoptic key is given to taxa of section Hypoxylon.

Some species of Nodulisporium

Six species of Nodulisporium are discussed. One is the anamorph of Hypoxylon truncatum while the teleomorph of the others is unknown, although Nodulisporium sylviforme sp.nov. may prove to be the anamorph of a Hypoxylon species. Four new combinations in Nodulisporium are proposed.

Metabolites of the higher fungi. Part 21. 3-Methyl-3,4-dihydroisocoumarins and related compounds from the ascomycete family xylariaceae

Culture solutions of members of the ascomycete family Xylariaceae produce a series of 5-substituted 8-hydroxy-3-methyl-3,4-dihydroisocoumarins as major metabolites. Ramulosin, iso-ochracein, and mellein are produced by three Hypoxylon species and 4-hydroxy iso-ochracein by one species. The antibiotic pyrenophorin is produced by Nummularia broomeiana. The synthesis of 7-formylmellein from mellein is described and the products from the alkaline rearrangement of 5-formylmellein are studied spectroscopically.

Two new Hypoxylon species from Gabon

Two new Hypoxylon species are described from Gabon. Hypoxylon atroroseum sp. nov. has rose-colored stromata with black papillate ostioles originating from depressed discs. Hypoxylon musceum sp. nov. has minute green stromata with umbilicate ostioles.

A new Hypoxylon species from Wales

A new Hypoxylon species with ridge-like ornamentation on the ascospore, H. chestersii, is described. The fungus was collected in Wales.

A new Hypoxylon species with appendaged, ornamented ascospores

A new Hypoxylon species with a cellular appendage on the ascospore, H. weldenii, is described. The fungus, collected in Louisiana, differs from other described Hypoxylon species in having ascospores with longitudinal valley-like depressions in the wall.

Stromal pigments and taxonomy of Hypoxylon.

Stromal pigments extracted with ethyl acetate from a variety of Hypoxylon species were examined by thin-layer chromatography and the results are discussed in relation to the taxonomy of the genus. Most species exhibited constant and characteristic pigment band patterns which in some cases proved to be useful in identification.

NUMMULARIA BROOMEIANA: CONIDIAL STATE AND TAXONOMIC ASPECTS

The hyphomycetous state of Nummularia broomeiana (Berk. and Curt.) J. H. Miller produces conidia blastically from conidiogenous cells borne on swollen vesicular apices of long unbranched or sparingly branched conidiophores. This conidial state is referable to Basidiobotrys Höhnel and is similar to conidial states previously described for Hypoxylon punctulatum and H. tinctor. Nummularia broomeiana also has stromatal developmental features reminiscent of the above Hypoxylon species, further indicating a close taxonomic alliance among them.

Numerical taxonomy of Hypoxylon: III. Comparison of the cultural states of some Hypoxylon species with Nodulisporium species

In a numerical analysis based on cultural characters a strong similarity was shown to exist between species of Nodulisporium Preuss and those species of Hypoxylon Bull ex Fr. which possess nodulose imperfect states.

Nuclear phenomena in the ascospores of Hypoxylon punctulatum

The ascospores of Hypoxylon punctulatum are uninucleate when formed, becoming multinucleate as they mature. It is the first Hypoxylon species to show regularly multinucleate ascospores. The chromosome number apparently is n = 4.

Hypoxylon Multiforme: Cytology of the Ascus

Hypoxylon multiforme Fr. is a common inhabitant of Betula and other woody genera throughout the cooler parts of the North Temperate Zone. It is the type species of Section Papillata and of Subsection Papillata of Hypoxylon, as delineated in Miller's monograph (6). The only other undoubted Hypoxylon species to have been studied cytologically heretofore are H. pruinatum (Klotzsch) Cke. \? H. mammatum (Wahlenb.) J. H. Miller ] (8) and H. fuscum Pers. ex Fr. (10), members of Section Papillata, Subsection Primo-cinerea and Section Hypoxylon, respectively. The cytological study of H. multiforme, re? ported here, is part of a continuing investigation by the author on the biology, cytology, and development of Hypoxylon species.