The Ganoderma weberianum-resinaceum lineage: multilocus phylogenetic analysis and morphology confirm G. mexicanum and G. parvulum in the Neotropics

Many species of Ganoderma exhibit a high phenotypic plasticity. Hence, particularly among them, the morphological species concept remains difficult to apply, resulting in a currently confused taxonomy; as a consequence, the geographical distribution range of many species also remains very uncertain. One of the areas with a strong uncertainty, as far as morphological species concept is concerned, is the Neotropics. It is common that names of species described from other regions, mainly from northern temperate areas, have been applied to Neotropical species. The aim of the present study was to determine which species might lay behind the G. weberianum complex in the Neotropics, using morphological studies and phylogenetic inferences based on both single (ITS) and multilocus (ITS, rpb2, and tef1-α) sequences. The results indicated that G. weberianumsensu Steyaert, which is the usually accepted concept for this taxon, was absent from the Neotropics. In this area, G. weberianumsensu Steyaert encompassed at least two phylogenetic species, which are tentatively, for the time being, identified as belonging to G. mexicanum and G. parvulum. These two species could be distinguished morphologically, notably by the ornamentation or its absence on their chlamydospores. The results also showed that additional species from the Neotropics might still exist, including, e.g., G. perzonatum, but their circumscription remains uncertain until now because of the paucity of material available. Furthermore, it was found that the current concept of G. resinaceum embraced a complex of species.

The genus Syrrhoe (Crustacea, Amphipoda, Synopiidae) from the North Atlantic

Three species of the amphipod genusSyrrhoeare described from the North Atlantic. The differences between these species are primarily the patterns of serration of the posterior margins of pleonite 3 and urosomite 1 and 2:Syrrhoeaffinishas a wide convex space on the posterior margin between the epimeron 3 and the dorsal serration. InSyrrhoecrenulataandSyrrhoeanneheleneaesp. nov.there is only a small notch on the posterior margin of pleonite 3.Syrrhoeanneheleneaesp. nov., otherwise similar toS.crenulata, has an additional serration on the posterior margin of urosomite 1. The inter- and intraspecific distances analyzed from COI confirm the morphological species concept of North AtlanticSyrrhoe.

A taxonomic monograph of the fern genus Ctenitis (Dryopteridaceae) in South America

Based on collections of 45 Herbaria in addition to newly collected specimens and some field observations, a taxonomic treatment for South American Ctenitis is provided, a hundred years after Christensen’s monographs. Guided by morphological species concept, 26 taxa are recognized (23 species and three varieties). A key including all taxa is provided, and all species are fully morphologically described, with information on distribution and habitat. Brazil is the richest country with 22 taxa, of which 13 are endemic, restricted mainly to Atlantic Forest. Taxa occurring in the other South American countries are also widely distributed in Mesoamerica and West Indies, except C. megalastriformis, only known from Peru, and C. refulgens var. peruviana, recorded in Peru and Bolivia. We dealt with 163 names that apply to the South American species. In addition, we propose three new combinations, and designate 38 lectotypes and three neotypes.

Rhoicosphenia kloseri, a new isopolar Rhoicosphenia (Bacillariophyta) species from the Antarctic with comparison to other isopolar Rhoicosphenia

Rhoicosphenia is a common diatom in both freshwater and marine ecosystems and the genus can be found on nearly every continent. Despite the fact that the genus is common, few new species have been reported from outside of Europe, Asia, and North America, and only one species has been previously described from the Antarctic. Further, most Rhoicosphenia are heteropolar in valve outline, asymmetrical to the transapical axis, while few taxa are isopolar. During investigations into the epiphytes on the red alga Georgiella confluens from the South Shetland Islands, a new marine, isopolar Rhoicosphenia was discovered and is herein described and documented with both light and scanning electron microscopy. Rhoicosphenia kloseri is isopolar, and in that regard similar to other isopolar taxa, such as R. genuflexa and R. pullus, but does not fit the morphological species concept of those taxa and is thus described as new. This new species discovery is following a trend of high rates of discovery of previously ignored morphological diversity within the genus Rhoicosphenia.

Automated and Unbiased Image Analyses as Tools in Phenotypic Classification of Small-Spored Alternaria spp.

For more than 25 years, controversy has surrounded the characterization and differentiation of small-spored Alternaria spp. And, therefore, the application of names of several species that are involved in the pathology of diseases related to host-specific toxin production. The name A. alternata often has been broadly applied to various morphologically and chemically distinct groups of isolates from different hosts. The purpose of this study was to develop and evaluate automated and unbiased image analysis systems that will analyze different phenotypic characters and facilitate testing and application of the morphological species concept in Alternaria taxonomy. Host-specific toxin-producing Alternaria isolates assigned to five morpho-species were compared with representative isolates of morphologically distinct A. alternata. Combined results of growth rates at different temperatures, colony morphology, and metabolite profiles were found to be useful in characterization and differentiation of small-spored Alternaria spp. when standardized conditions are applied and representative isolates employed for comparison.