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About a thousand described species of Myxomycetes, colloquially named slime moulds, are present in most terrestrial habitats. Molecular environmental sampling has revealed that a significant proportion of sequences could not be assigned to known species, with some specific groups showing a high hidden diversity. One such group included Stemonitis and allied genera, with only a few closely related reference sequences from known species and many distantly related sequences from environmental sampling. To improve the phylogeny and help define genera in this lineage, we provided nine new small-subunit ribosomal RNA gene sequences of Stemonitis and allied genera, along with microscopy observations. We showed that the genus Stemonitis is polyphyletic, clearly separated into two groups, with the main distinguishing feature being spore ornamentation. The first group included the type species Stemonitis fusca, and was characterized by reticulated spores, while the second contained species with warted spores (e.g. S. flavogenita and S. axifera) and many undetermined environmental sequences. In addition, we show that the related genera Stemonitopsis, Stemonaria and Symphytocarpus were polyphyletic and that their circumscription was based on inconsistent characteristics. Instead, representatives of these genera clustered into the two clades according to their spore ornamentation. Our study provides a first insight into the genetic diversity of Stemonitis and allied genera, and proposes spore ornamentation as an evolutionary informative feature to distinguish genera in this group.

As a result of a field study, carried out in August 2019, 25 species of myxomycetes from 17 genera, 7 families, 6 orders and 2 subclasses of the class Myxomycetes were collected in the area of the Seymskyi Regional Landscape Park (Sumy region, Ukraine). According to the bias-corrected Chao1 estimator, the collection represents 77.6% of the myxomycetes species composition of the park. The biodiversity indexes of the studied biota are as follows: Margalef’s diversity index – 13.7, Shannon’s index – 1.32, Simpson’s index – 0.06, Pielou’s index – 0.28. All identified species are new to the Ukrainian part of the Central Russian Upland forests. One of them, Comatricha anomala, found on the dead wood of Betula pendula, is new to Ukraine. Among the substrate groups of myxomycetes, xylophilic (18 species, 65.4%) and corticolous (8; 31%) species dominate in the park. Arcyria cinerea and Stemonitis pallida demonstrate a mixed substrate strategy. Among the substrate-forming plants, the greatest diversity of myxomycetes was observed on substrates, formed by relatively unabundant plant species: Populus tremula (13 myxomycete species, 50.0%), Quercus robur (11; 42.3%) and Bbetula pendula (8 species; 30.8%), while only 6 species of myxomycetes (23.1%) were found on the dominant plant species of P. sylvestris. Among the orders of myxomycetes, by number of species, Stemonitidales (11 species; 42.3%) and Trichiales (8 species; 30.8%) prevail in the park, among the families the most abundant were Amaurochaetaceae (6; 23.1%) and Trichiaceae (8; 30.8%), among the genera they are Arcyria (4; 15.4%), Lycogala, Stemonitis, Stemonitopsis and Comatricha (2 species each; 7.7%). The taxonomic structure of myxomycete biota differs significantly on the substrates, formed by different plant species. According to the ratio between species Trichiales and Stemonitidales, the substrate-forming plants form the following row: P. sylvestris, B.pendula, P.tremula, R. pseudoacacia and Q. robur (3.0 → 1.5 → 1.5 → 0.5 → 0.25 correspondingly)

* Stemonitopsis hyperopta (Meyl.) Nann. -Bremek. (2 FC, 2 loc, 1 ps) Loc. 39c La Digue: On wood of rotten log of Calophyllum inophyllum, AM2973, TK2544. Loc. 41b La Digue: On wood of large cut log of Calophyllum inophyllum, AM2971, TK2541., Published as part of Kryvomaz, Tetiana, Michaud, Alain & Stephenson, Steven L., 2020, Myxomycete biodiversity on five islands of the Seychelles, pp. 201-244 in Zootaxa 4851 (2) on page 242, DOI: 10.11646/zootaxa.4851.2.1, http://zenodo.org/record/4407410

* Stemonitopsis gracilis (G. Lister) Nann. -Bremek. (1 FC, 1 loc, 1 ps) Loc. 42b La Digue: On dead wood of Calophyllum inophyllum, AM2946, TK2509., Published as part of Kryvomaz, Tetiana, Michaud, Alain & Stephenson, Steven L., 2020, Myxomycete biodiversity on five islands of the Seychelles, pp. 201-244 in Zootaxa 4851 (2) on page 242, DOI: 10.11646/zootaxa.4851.2.1, http://zenodo.org/record/4407410

Seven different PCR primers targeting 18 different myxomycetes genera were designed and ribosomal DNA ITS1-5.8SrDNA-ITS2 regions of 52 morphologically characterized species from Turkey were amplified and sequenced. The studied species belong to the genera Arcyria, Badhamia, Ceratiomyxa, Collaria, Comatricha, Cribraria, Diachea, Diderma, Didymium, Enerthenema, Lamproderma, Lycogala, Perichaena, Physarum, Reticularia, Stemonitis, Stemonitopsis, and Trichia. Significant ITS region size and sequence variations were observed among the analyzed species. The ITS based phylogenetic tree did not reflect evolutionary relationships at genus or higher level. The only exception was the genus Didymium, which formed a clearly distinctive cluster in the phylogenetic tree containing 18 different genera. It was concluded that interspecies variation of the ITS1-5.8S-ITS2 region is high enough to differentiate species, but this region did not reflect the evolutionary relationships between the myxomycetes species. Hence, we suggested that sequencing of the ITS region could only be used as a supporting tool for the phenotypic identification, not for revealing the evolutionary relationships between the myxomycetes species.

For the first time both Light- and Scanning Electron Microscopy are aplied to re-assess diagnostic characters of type specimens for selected Stemonitales kept in the collections of the Natural History Museum London (BM). The results are used to revise published data and the type status is discussed for specimens of Amaurochaete comata G. Lister & Brândză, Comatricha longipila Nann.-Bremek., Comatricha lurida Lister, Comatricha pulchella (C. Bab.) Rostaf., Comatricha suksdorfii Ellis & Everh., Paradiacheopsis rigida (Brândză) Nann.-Bremek., Stemonaria irregularis (Rex) Nann.-Bremek., R. Sharma & Y. Yamam. and Stemonitopsis microspora (Lister) Nann.-Bremek at BM. A lectotype is proposed for Paradiacheopsis rigida (Brândză) Nann.-Bremek.

KEMALPASA VE CEVRESI (IZMIR) MIKSOBIOTASININ BELIRLENMESI Bu arastirma Ekim-2013 ile Temmuz 2014 arasinda Kemalpasa (Izmir) ve cevresinde belirlenen alanlarda miksomisetlerin bulunusu ve dagilimini belirlemek uzere yapilmistir. Calismada genellikle Quercus sp. ve Pinus sp. agaclari basta olmak uzere, yaprak dokuntuleri, canli agaclarin olu kabuklari ve toprak ornekleri olmak uzere 11 lokaliteden 91substrat toplanmistir. Her bir calisilan alan icin, miksomisetler hem dogal substratlar uzerinde hem de nemli oda kulturu ile belirlenerek karakterizasyonlari yapilmistir. Sicaklik, nem ve isik yogunlugu gibi cevresel faktorler gercek zamanli olarak olculmus ve buna bagli turlerin dagilimi tartisilmistir. Sonuclarimiza gore, 10 familyaya ait 29 tur (7’si dogal) ve 1 cins bazinda olmak uzere toplam 30 takson tanilanmistir. Turlerin cogunlugu (%77) nemli oda kulturunden, digerleri (%23) dogal olarak elde edilmis olup, belirlenen 16 cins sirasiyla; Ceratiomyxa, Echinostelium, Cribraria, Lycogala, Licea, Arcyria, Perichaena, Trichia, Didymium, Physarum, Collaria, Comatricha, Enerthenema, Macbrideola, Stemonitis ve Stemonitopsis’dir. Calisilan alanlardaki miksomiset dagilimlari genellikle benzerlik gostermekte ve belirlenen cogu tur kozmopolittir. Arastirma alaninda belirlenen en yaygin tur ise Arcyria cinerea’ dir. DETERMINATION THE MYXOBIOTA OF KEMALPASA AND SURROUNDING (IZMIR) This research assessed the occurrence and distribution of myxomycetes, and it was carried out in theselected surrounding areas of Kemalpasa, (Izmir) between October 2013 and July 2014. A total of 91 specimensin 11 localities were collected in Quercus sp. and Pinus sp. plants were the most common type of substrateinvestigated, but leaf litter, dead barks of living trees and soil materials were also included in the survey. Myxomycetes were determined and characterized both on natural substrates and in the moist chambers for each ofthe study sites. Environmental factors such as temperature, humidity and light intensity were analyzed with realtime and occurrence of some species was discussed. The obtained results showed that a total of 30 taxa representing 29 species (7 species naturally) with 1 genus belonging to 10 families were identified. Most of the species collected from prepared moist chambers (77%) and others from naturel (23%) resulted in 16 genera including Ceratiomyxa, Echinostelium, Cribraria, Lycogala, Licea, Arcyria, Perichaena, Trichia, Didymium, Physarum, Collaria, Comatricha, Enerthenema, Macbrideola, Stemonitis and Stemonitopsis. A comparison of the distribution of myxomycete showed similarities in this area and many species were reported as cosmopolite. Arcyria cinerea was the most wide spread species in the research area.

First records of myxomycetes in the North region of Brazil go back to the 19th century. Nevertheless, the myxobiota of this region is still largely unexplored, with only 42 species recorded, distributed in 20 genera and seven families. The objectives of this paper were to characterize the Myxomycetes collection of the Herbarium of the Federal University of Roraima (UFRR) and to add new records for the myxobiota of this State. The collection holds specimens collected in fragments of Open Ombrophilous Forest, Seasonal Semi-deciduous Forest, Riparian Forest, deforested areas and urban home gardens in the state of Roraima. The 157 exsiccates were analyzed and identified or redetermined based on identification keys, descriptions and illustrations. The collection is in good conditions of preservation and includes all subclasses of Myxomycetes, 83% of its orders, 50% of its families, and 20 species. Trichiales, with one family, three genera and six species, represents 62% of all exsiccates. Cribraria aff. splendens, Metatrichia vesparia, Physarella oblonga, Stemonaria longa and Stemonitis splendens are new records for Roraima and Arcyria obvelata, Comatricha pulchella, Stemonitis pallida and Stemonitopsis aequalis are referred for the first time in the Northern Region, enlarging the knowledge of the Brazilian geographic distribution of these species. Os primeiros registros de mixomicetos na Região Norte do Brasil remontam ao Século XIX. Todavia, a mixobiota desta região está ainda muito pouco explorada, com apenas 42 espécies registradas, distribuídas em 20 gêneros e sete famílias. Os objetivos deste estudo foram caracterizar a coleção de Myxomycetes do Herbário da Universidade Federal de Roraima (UFRR) e adicionar novos registros para a mixobiota deste estado. A coleção contém espécimes coletados em fragmentos de Floresta Ombrófila Aberta, Floresta Estacional Semi-decidual, Mata Ciliar, áreas desmatadas e quintais urbanos no estado de Roraima. As 157 exsicatas foram analisadas e identificadas ou redeterminadas com base em chaves de identificação, descrições e ilustrações. A coleção encontra-se em boas condições de conservação e inclui todas as subclasses de Myxomycetes, 83% das ordens, 50% das famílias e 20 espécies. A ordem Trichiales, com uma família, três gêneros e seis espécies, corresponde a 62% das exsicatas. Cribraria aff. splendens, Metatrichia vesparia, Physarella oblonga, Stemonaria longa e Stemonitis splendens são novos registros para o estado de Roraima e Arcyria obvelata, Comatricha pulchella, Stemonitis pallida e Stemonitopsis aequalis são referidas pela primeira vez para a Região Norte, ampliando a distribuição geográfica conhecida para estas espécies no Brasil.

Myxomycetes (plasmodial slime moulds) are best known from temperate and boreal forests, where they are commonly found in association with decaying coarse woody debris and leaf litter on the forest floor (Martin & Alexopoulos 1969). There have been only a few reports of myxomycetes from either the continent of Antarctica or the subantarctic islands. In what apparently represents the first record of a myxomycete from the south polar region, Horak (1966) described a new species, Diderma antarcticolum Horak, from material collected on the Antarctic Peninsula (64°53′S, 62°53′W). Later, Ing & Smith (1980,1983) reported Didymium dubium Rost., Lamproderma arcyrioides (Sommerf.) Rost., Stemonitopsis (Comatricha) subcaespitosa (Peck) Nann.- Brem. and Diderma niveum (Rost.) Macbr. from South Georgia (54–55°S, 36–38°W). They also indicated that the latter species was known from Signy Island, South Orkney Islands (60°43′S, 45°36′W) and the Antarctic Peninsula (65°16′S, 64°08′W) as well as South Georgia.