A powdery mildew fungus occurring on leaves of Corylopsis pauciflora and C. spicata in Japan is described as a new species, Erysiphe corylopsidis. This species is characterized by fewer than 15 appendages on a chasmothecium, primary branches of the appendages occasionally elongated, and a relatively small number (2–5) of ascospores per ascus. Molecular phylogenetic analyses based on rDNA ITS and 28S rDNA sequences indicate that this fungus forms an independent lineage in the genus Erysiphe.

Polyporus longiporus, belonging to group Polyporellus, is newly reported from Japan in what also constitutes the second report of the species since its original description. This species is characterized by radially elongated pores, smooth and brown to dark brown pileus, and cylindrical and slightly curved basidiospores. Phylogenetic analysis based on the ITS region revealed that P. longiporus forms a terminal, strongly supported clade that is closely related to P. ciliatus. A description and illustrations of the present species and a key to the species of group Polyporellus are provided.

To clarify the factors affecting fungal contamination in bathrooms, the growth of 13 common fungal species (13 isolates) in bathrooms was studied under various environmental conditions. Most of the fungi examined grew on media of 0.01% and 0.05% sodium fatty acid and on media of 0.01% anion surfactant. On media of non-ion surfactant, however, growth varied from species to species. Fungi found commonly in bathrooms can be divided into two groups. The first group, including six species – Cladophialophora boppii, Exophiala spinifera, E. salmonis, Phialophora europaea, Phoma herbarum, and Scolecobasidium constrictum – grew on media of 0.01%, 0.05%, and 0.25% non-ion surfactant, with the latter five species also growing on alkali medium. Most of them did not grow at 33°C, or on media with 10%NaCl, however. Fungi of these six species, identified using DNA and morphological analysis, were common in bathrooms, but not in other indoor environments, for example, in house dust or on windows. The second group contained seven species including Aureobasidium sp., Cladosporium cladosporioides, and Fusarium sp., which were common both in house dust and in bathrooms; they did not grow on media of 0.05% or 0.25% non-ion surfactant, but most grew comparatively fast on normal medium (1/4PDA), and were able to grow on media with 10%NaCl and also at 33°C. The characteristic fungi found in bathrooms were able to exploit surfactant but were unable to grow well under comparatively dry or hightemperature conditions.

Typhula maritima on coastal dunes in Ishikari and Yoichi, Hokkaido, northern Japan, is illustrated as a new species on the basis of morphology and molecular evidence. The sclerotia in the sand had mycelial strands that extended upward to support basidiocarps. Mycelial strands also connected sclerotia with plant tissues of the dunegrass Eylmus mollis Trin. Typhula maritima is psychrotrophic and halotrophic, and sclerotia floated on seawater for 1 week. These physiological characteristics are important factors for adaptation to the coastal dune environment. Inoculation tests indicated that T. maritima could grow on living E. mollis, but it was not pathogenic. The results suggested that this fungus was, at least, not an active pathogen in the coastal dune ecosystem. Ex-holotype is TH-AIST-Tm-1 (= NBRC 104266).

Asterosporium orientale, described on Betula ermanii, is transferred to the genus Prosthemium, and a new combination, P. orientale, is proposed. Because of the morphological similarities, P. asterosporum originally described from twigs of B. pendula is considered as a synonym of P. orientale.

Sixty-two isolates from basidiocarps of Armillaria spp. were obtained from Hokkaido Island, northern Japan. Six species (Armillaria cepistipes, A. gallica, A. nabsnona, A. ostoyae, A. sinapina, and an undescribed species, “Nag. E”) were identified by pairing tests with known tester strains and one subspecies (Armillaria mellea subsp. nipponica, a non-heterothallic form of A. mellea) was identified by its macro and micro-morphological characters of the basidiocarps. This is the first case of “Nag. E” being reported from Hokkaido Island.

A simple method for isolating the nuclei from Basidiobolus ranarum was established. To improve the yield and purity of nuclei, we investigated maceration methods, buffer composition, and centrifugation conditions to establish an optimal procedure. Basidiobolus ranarum cultured for 5 days was enzymatically macerated and then homogenized and filtrated through stainless steel sieves. The crude cell homogenate was loaded on a layer of buffer containing 50% glycerol and centrifuged at 1500g. The resultant pellet contained pure nuclei.

Haploporus subtrameteus, a rare polypore, is newly reported for Japan. This fungus was known only from three localities in the Russian Far East, Altai Mts., and three in China. The Japanese material was on a dead tree of Padus grayana around Aokigahara-marubi, Mt. Fuji. This article gives detailed morphology based on the Japanese collection and a photo in the natural habitat.