A ruby-colored Pseudobaeospora species is described as new from material collected on the island of Hawaii.

Pseudobaeospora wipapatiae is described as new based on material collected in alien wet habitats on the island of Hawaii. Unique features of this beautiful species include deep ruby-colored basidiomes with two-spored basidia, amyloid cheilocystidia and a hymeniderm pileipellis with abundant pileocystidia that is initially deep ruby in KOH then changes to lilac gray. Phylogenetic analysis of nuclear large ribosomal subunit sequence data suggest a close relationship between Pseudobaeospora and Tricholoma. BLAST comparisons of internal transcribed spacer and 5.8S nuclear ribosomal subunit regions sequence data reveal greatest similarity with existing sequences of Pseudobaeospora species. A comprehensive description, color photograph, illustrations of salient micromorphological features and comparisons with phenetically similar taxa are provided.

Testing the "one-log-one-genet" hypothesis: methodological challenges of population sampling for the Hawaiian wood-decay fungus Rhodocollybia laulaha.

We test our "one-log-one-genet" sampling method for the Hawaiian mushroom Rhodocollybia laulaha that posits all R. laulaha mushrooms collected from a single log represent a single genet. We also examine the potential expansion of single genets beyond the confines of one log and the temporal persistence of genets in nature. Finally, we estimate error rates in AFLP scoring. To our knowledge, this is one of few examinations of naturally occurring fungal genets in the tropics and a novel report of AFLP error rates in fungi. Forty-six mushrooms from seven logs were genotyped with the IGS1 locus, two microsatellite loci and 184 AFLP loci from three primer pair combinations. One hundred fifty-three mushroom collections representing the geographic range of R. laulaha were genotyped with the IGS1 and microsatellite loci. The probabilities of two genets sharing identical multilocus genotypes by chance (without actually being the same genet) were calculated for each genotype recovered. The data suggest that R. laulaha mushrooms from one log typically represent one genet, that genets might expand beyond the confines of a single log and that a single genet may persist in a collecting site for as much as 13 y. We offer initial evidence to support the "one-log-one genet" sampling method and the idea that R. laulaha vegetative expansion and persistence in nature might be common. In addition, we caution against exclusive use of AFLP loci for identifying fungal genets due to relatively high error rates in scoring.

Investigating the allelic evolution of an imperfect microsatellite locus in the Hawaiian mushroom Rhodocollybia laulaha.

The evolutionary mechanisms that give rise to microsatellite alleles remain poorly understood in general and are especially understudied for fungal microsatellite loci. The unusual G28 microsatellite locus was developed from the Hawaiian mushroom Rhodocollybia laulaha. Here, we employ a novel approach to test for allele size homoplasy and examine competing mechanistic models of microsatellite evolution in the context of biogeographic expectations for this locus based on Hawaiian geologic history. Seven G28 alleles have been identified from a sampling of 153 individuals. The G28 locus is composed of a trinucleotide imperfect motif, which permits examination of the relationships between alleles and allows for detection of potential size homoplasy within the repetitive element. Alignment of G28 allele sequence data across multiple unrelated individuals suggests that alleles of like size are homologous within Hawaii. A variety of gap coding methods are explored in the inference of allele evolution. Length differences between alleles appear to be the result of polymerase slippage at multiple positions in the repetitive element, suggesting an intricate process of allelic evolution, which is not necessarily stepwise. Complex migration scenarios must be invoked to explain the current geographic distribution of alleles if their evolution was in fact sequential (from longest to shortest or from shortest to longest) as predicted by the "progression rule."

Agaricales of the Hawaiian Islands 9. Five new white-spored species from native montane wet forests.

Five new species of white-spored agarics are described from native montane wet forests in the Hawaiian Islands as follows: Callistosporium vinosobrunneum, Marasmiellus hapuuarum, Marasmius koae, Mycena marasmielloides, Pleurocybella ohiae. Comprehensive descriptions, illustrations and comparisons with phenetically similar species are provided. An itemization of the 24 known putatively endemic agarics described from this unique habitat is provided.