ABSTRACT
Nomenclatural type definitions are one of the most important concepts in biological nomenclature. Being physical objects that can be re-studied by other researchers, types permanently link taxonomy (an artificial agreement to classify biological diversity) with nomenclature (an artificial agreement to name biological diversity). Two proposals to amend the International Code of Nomenclature for algae, fungi, and plants (ICN), allowing DNA sequences alone (of any region and extent) to serve as types of taxon names for voucherless fungi (mainly putative taxa from environmental DNA sequences), have been submitted to be voted on at the 11th International Mycological Congress (Puerto Rico, July 2018). We consider various genetic processes affecting the distribution of alleles among taxa and find that alleles may not consistently and uniquely represent the species within which they are contained. Should the proposals be accepted, the meaning of nomenclatural types would change in a fundamental way from physical objects as sources of data to the data themselves. Such changes are conducive to irreproducible science, the potential typification on artefactual data, and massive creation of names with low information content, ultimately causing nomenclatural instability and unnecessary work for future researchers that would stall future explorations of fungal diversity. We conclude that the acceptance of DNA sequences alone as types of names of taxa, under the terms used in the current proposals, is unnecessary and would not solve the problem of naming putative taxa known only from DNA sequences in a scientifically defensible way. As an alternative, we highlight the use of formulas for naming putative taxa (candidate taxa) that do not require any modification of the ICN.
ABSTRACT
In this study, eight species of Chroogomphus are recognized from Europe: C. britannicus, C. aff. filiformis 1, C. fulmineus, C. cf. helveticus, C. mediterraneus, C. cf. purpurascens, C. rutilus, and C. subfulmineus. Different candidates for the application of the name C. rutilus are evaluated and the best fit to the description is selected; lecto- and epitypes are chosen to fix the name. Chroogomphus fulmineus and C. mediterraneus are also epitypified and a new species, C. subfulmineus, is described. The infrageneric classification is revised and a new subgenus Siccigomphus and three new sections, Confusi, Filiformes, and Fulminei are introduced. The former sections Chroogomphus and Floccigomphus are elevated to subgeneric level. Comparison of the ITS regions (nuc rDNA ITS1-5.8S-ITS2) of all species studied shows that there is a minimum interspecific difference of 1.5 %, with the exception of the two species belonging to sect. Fulminei which differ by a minimum of 0.9 %. Ecological specimen data indicate that species of Chroogomphus form basidiomes under members of Pinaceae, with a general preference for species of Pinus. Five European species have been recorded under Picea, while Abies and Larix have also been recorded as tree associates, although the detailed nutritional relationships of the genus, involving other suilloid fungi in particular, have yet to be fully clarified.
ABSTRACT
Since the nineteenth century, Myriostoma has been regarded as a monotypic genus with a widespread distribution in north temperate and subtropical regions. However, on the basis of morphological characters and phylogenetic evidence of DNA sequences of the internal transcribed spacer (ITS) regions and the large subunit nuclear ribosomal RNA gene (LSU), four species are now delimited: M. areolatum comb. & stat. nov., M. calongei sp. nov., M. capillisporum comb. & stat. nov., and M. coliforme. Myriostoma coliforme is typified by selecting a lectotype (iconotype) and a modern sequenced collection as an epitype. The four species can be discriminated by a combination of morphological characters, such as stomatal form, endoperidial surface texture, and basidiospore size and ornamentation.
