Notes on Amanita section Validae in Hainan Island, China

Downfall of an empire: Unmasking the hidden diversity and distribution of the Amanita rubescens species complex

Amanita is one of the most salient mushroom genera due to its cultural, economic, and medical importance. Recently, many new Amanita species have been described worldwide, increasing the genus richness. However, several clades have cryptic diversity, and many species complexes have not yet been resolved. This is the case of the rubescent species in the Validae section, which have been widely cited under the name Amanita rubescens s.l. We used a four-locus matrix (nuc rDNA internal transcribed spacer [ITS] and 28S regions and genes for RNA polymerase II subunit 2 [rpb2], translation elongation factor 1-α [tef1-α], and β-tubulin [tub2]) to solve the phylogenetic relationships within the Amanita section Validae. To analyze the diversity and distribution patterns of species, we used an extensive ITS sequence sampling including environmental DNA databases. The phylogenetic analyses demonstrated that the Validae section is divided into three monophyletic and highly supported major clades: Mappae, Validae, and Rubescentes. At least 11 species-level clades within the Rubescentes clade were highly supported: A. cruentilemurum nom. prov. A. brunneolocularis, A. rubescens s.s. (European clade), A. rubescens s.s. (Asiatic clade), A. orsonii s.s. A. 'orsonii,' A. aureosubucula nom. prov., A. novinupta, A. flavorubens, and two undescribed North American species. We proved that A. rubescens s.s. has two segregated populations (European and Asiatic) and it is not naturally distributed in America. Furthermore, we found that America has more cryptic species within the Rubescentes clade than Eurasia.

Four New Species and a New Combination of Boletaceae (Boletales) from Subtropical and Tropical China

Previous studies have shown that boletes are abundant and diverse in China, especially in tropical and subtropical regions. In the present study, morphological, ecological, host relationship, and a four-locus (28S, tef1, rpb1, and rpb2) molecular phylogenetic analyses were used to study the family Boletaceae in subtropical and tropical China. Four new bluing species are described from three genera, viz. Boletellus verruculosus (Chinese name), Xerocomellus tenuis (Chinese name), Xer. brunneus (Chinese name), and Xerocomus zhangii (Chinese name). Moreover, the genus Nigroboletus is treated as a synonym of Xerocomellus, and a new combination, namely Xer. roseonigrescens (Chinese name), is proposed.

Morphophylogenetic evidence reveals four new fungal species within Tetraplosphaeriaceae (Pleosporales, Ascomycota) from tropical and subtropical forest in China

Tetraplosphaeriaceae (Pleosporales, Ascomycota) is a family with many saprobes recorded from various hosts, especially bamboo and grasses. During a taxonomic investigation of microfungi in tropical and subtropical forest regions of Guizhou, Hainan and Yunnan provinces, China, several plant samples were collected and examined for fungi. Four newly discovered species are described based on morphology and evolutionary relationships with their allies inferred from phylogenetic analyses derived from a combined dataset of LSU, ITS, SSU, and tub2 DNA sequence data. Detailed illustrations, descriptions and taxonomic notes are provided for each species. The four new species of Tetraplosphaeriaceae reported herein are Polyplosphaeriaguizhouensis, Polyplosphaeriahainanensis, Pseudotetraploayunnanensis, and Tetraploahainanensis. A checklist of Tetraplosphaeriaceae species with available details on their ecology is also provided.

Diversity and taxonomy of the genus Amanita (Amanitaceae, Agaricales) in the Yanshan Mountains, Northern China

Globally, the species of Amanita are key components of ectomycorrhizal ecosystems. Some of them are widely known as poisonous or edible fungi. Although many new Amanita species from China have been described, the species diversity of Yanshan Mountains remains unknown. We here describe three new species, namely, A. borealis sp. nov. (Sect. Amanita), A. brunneola sp. nov. (Sect. Caesareae), and A. yanshanensis sp. nov. (Sect. Validae), based on morphological observations and molecular phylogenetic analyses. In addition, nine known species, namely, A. caesareoides (Sect. Caesareae), A. chiui (Sect. Vaginatae), A. muscaria (Sect. Amanita), A. oberwinklerana (Sect. Roanokenses), A. ovalispora (Sect. Vaginatae), A. subglobosa (Sect. Amanita), A. subjunquillea (Sect. phalloideae), A. vaginata var. vaginata (Sect. Vaginatae), and A. virosa (Sect. phalloideae), were reported from Yanshan Mountains for the first time. Our results emphasize that China has a high diversity of Amanita species and that additional studies are required to understand the exact species number. These findings play a crucial role in Amanita toxin research and ecological conservation. This study investigated the areas where Amanita species-related research is lacking. The study also attempted to better understand Amanita distribution and thus contribute to related research. This study enriches the species diversity of Amanita in Yanshan Mountains and offers additional data supporting the macrofungal systematics, toxin research, and diversity and ecological studies of Amanita in future studies.

Species Diversity of Amanita Section Vaginatae in Eastern China, with a Description of Four New Species

Species of Amanita sect. Vaginatae (Fr.) Quél. are challenging to delimitate due to the morphological similarity or morphostasis among different taxa. In this study, a multi-locus (nuc rDNA region encompassing the internal transcribed spacers 1 and 2 with the 5.8S rDNA, the D1-D3 domains of nuc 28S rDNA, partial sequences of translation elongation factor 1-a, and the second largest subunit of RNA polymerase II) phylogeny was employed to investigate the species diversity of the section in eastern China. Sixteen species were recognized, including four new species; namely, A. circulata, A. multicingulata, A. orientalis, and A. sinofulva. They were documented with illustrated descriptions, ecological evidence, and comparisons with similar species. A key to the species of the section from eastern China is provided.

Taxonomic Novelties and New Records of Amanita Subgenus Amanitina from Thailand

The Amanita subgenus Amanitina contains six sections, and the species diversity of this subgenus has still not been explored in Thailand. Twenty samples collected in 2019 and 2020, which had the morphological characteristics of the Amanita subgen. Amanitina, were observed in this study. Both the microscopical characteristics and multi-gene phylogenetic analyses of the ITS, nrLSU, RPB2, TEF1-α, and TUB gene regions revealed that the 20 samples represented nine species and dispersed into four sections. Remarkably, three taxa were different from any other currently known species. Here, we describe them as new to science, namely A. albifragilis, A. claristriata, and A. fulvisquamea. Moreover, we also recognized six interesting taxa, including four records that were new to Thailand, viz. A. cacaina, A. citrinoannulata, A. griseofarinosa, and A. neoovoidea, as well as two previously recorded species, A. caojizong and A. oberwinkleriana. Moreover, we provide the first RPB2 and TEF1-α gene sequences for A. cacaina. Detailed descriptions, illustrations as line drawings, and comparisons with related taxa are provided.