Notes on Amanita section Caesareae from Malaysia.

Some Amanita specimens collected from Malaysia are critically investigated by morphological examination and molecular analysis of two gene fragments, the nuc rDNA partial 28S (28S) gene and the internal transcriber spacer (ITS1-5.8S-ITS2 = ITS) regions. Six phylogenetic species of Amanita section Caesareae are recognized among the studied collections. One of them is described as new, A. malayensis. Four of the phylogenetic species correspond with existing morphology-based taxa: A. aporema, A. javanica, A. princeps, and A. similis. The remaining species is not described because of the paucity of material. Detailed descriptions and the distribution of these southeastern Asian species are provided, along with a key to the species of section Caesareae from Malaysia.

Amanita lippiae: a new species from the semi-arid caatinga region of Brazil.

Amanita lippiae is described as a new species from a semi-arid (caatinga) region of northeastern Brazil. It possesses clampless basidia and elongate to nearly cylindrical inamyloid basidiospores, bears irregular remains of universal veil on the stipe bulb and is a gemmatoid species assignable to Amanita sect. Amanita.

Amanita viscidolutea, a new species from Brazil with a key to Central and South American species of Amanita section Amanita.

We described and illustrated Amanita viscidolutea sp. nov. from specimens collected in the state of Rio Grande do Norte, northeastern Brazil. The main characteristics of the new species are its yellow pileus with white margin, the viscidity of the pileal surface, an exannulate stipe and inamyloid basidiospores. We also present an artificial dichotomous key to Central and South American species of Amanita (subgenus Amanita) section Amanita.

Beringian origins and cryptic speciation events in the fly agaric (Amanita muscaria).

Amanita muscaria sensu lato has a wide geographic distribution, occurring in Europe, Asia, Africa, Australia, New Zealand, and North, Central and South America. Previous phylogenetic work by others indicates three geographic clades (i.e. 'Eurasian', 'Eurasian-alpine' and 'North American' groups) within A. muscaria. However, the historical dispersal patterns of A. muscaria remained unclear. In our project, we collected specimens from arctic, boreal and humid temperate regions in Alaska, and generated DNA sequence data from the protein-coding beta-tubulin gene and the internal transcribed spacer (ITS) and large subunit (LSU) regions of the ribosomal DNA repeat. Homologous sequences from additional A. muscaria isolates were downloaded from GenBank. We conducted phylogenetic and nested clade analyses (NCA) to reveal the phylogeographic history of the species complex. Although phylogenetic analyses confirmed the existence of the three above-mentioned clades, representatives of all three groups were found to occur sympatrically in Alaska, suggesting that they represent cryptic phylogenetic species with partially overlapping geographic distributions rather than being allopatric populations. All phylogenetic species share at least two morphological varieties with other species, suggesting ancestral polymorphism in pileus and wart colour pre-dating their speciations. The ancestral population of A. muscaria likely evolved in the Siberian-Beringian region and underwent fragmentation as inferred from NCA and the coalescent analyses. The data suggest that these populations later evolved into species, expanded their range in North America and Eurasia. In addition to range expansions, populations of all three species remained in Beringia and adapted to the cooling climate.

Production and characterization of Amanitin toxins from a pure culture of Amanita exitialis.

Amanita exitialis Zhu L. Yang and T.H. Li is a lethal mushroom species recently isolated in Guangdong Province, China. In this report, a pure culture of this species was obtained for the first time. To confirm the identity of the pure culture, the internal transcribed spacer regions of the nuclear ribosomal DNA of the pure culture and of a typical fruiting body of the species were sequenced and compared. Further, amatoxins produced by pure cultures were analyzed and characterized by high-performance liquid chromatography and mass spectrometry analysis. The results showed that the pure cultures produced 728.3 +/- 43.8 microg g(-1) (dry matter) of alpha-Amanitin and 60.0 +/- 20.7 microg g(-1) (dry matter) of beta-Amanitin, respectively, a yield which is about 10% of that produced by fruiting bodies.

Small genets of Lactarius xanthogalactus, Russula cremoricolor and Amanita francheti in late-stage ectomycorrhizal successions.

We determined the size of genets of late-stage ectomycorrhizal fungi in field sites in coastal Northern California. Basidiocarps were collected, mapped and subjected to genetic fingerprinting using amplified fragment length polymorphisms (AFLPs). The minimum size estimates for the largest genets of Amanita francheti, Lactarius xanthogalactus and Russula cremoricolor were 1.5, 9.3 and 1.1 m2, respectively. The molecular markers also showed that R. cremoricolor is dimorphic, with red- and white-capped morphotypes of this species forming a continuous population. Our results suggest that spore propagation plays a much more important role in the life history of the Russulaceae in undisturbed forest settings than previously recognized. Fungi appearing late in the succession sequence and systems without obvious disturbance therefore do not necessarily colonize primarily by mycelium.

Renal failure caused by mushroom poisoning.

BACKGROUND: In the Pacific Northwest region of the US and in southwestern British Columbia, Canada, isolated cases of renal failure have occurred following ingestion of wild mushrooms. We report four cases in which toxic mushrooms were mistaken for the edible pine mushroom or matsutake (Tricholoma magnivelare). CASE REPORTS: Gastrointestinal symptoms started five to eight hours after ingestion and continued for several days. Three of the four patients were found to be in renal failure when they presented to the emergency department 5-6 days post ingestion. One patient, an elderly diabetic, had renal dysfunction the day following ingestion. All patients received hemodialysis and supportive care and regained renal function. DISCUSSION: Symptoms and time of onset are similar to those reported in previous cases of Amanita smithiana poisoning. This suggests that the mushroom involved in these cases may also be Amanita smithiana which contains nephrotoxic compounds. In one of the cases, stem ends of the mushrooms were available for examination. Cellular elements conforming to those described as being present in the species Amanita smithiana were seen on light microscopy. CONCLUSION: Mushroom field guides warn against mistaking Amanita smithiana for pine mushrooms. They are similar in size, color and habitat. It appears possible that Amanita smithiana mushrooms were eaten instead of pine mushrooms in these cases.

Amanita phalloides in Victoria.

Amanita phalloides is found regularly in suburban Melbourne and country areas where old oaks and other deciduous trees are grown as street trees, in parks, and in private gardens. This deadly poisonous mushroom may be mistaken for the edible Agaricus spp.