Abstract: Some new observations, relevant for specific, subgeneric and generic taxonomy, are presented on the characters of the species of Gyromitra Fr. and Pseudorhizina Jač. (Discomycetes, Pezizales), and the taxonomic significance of earlier known diagnostic features is dealt with and partly re-evaluated. On the basis of this information, it is considered that Pseudorhizina is a valid, independent genus, and that besides the type species, P. sphaerospora (Peck) Pouz., -it should also contain Gyromitra californica (Phill.) Rait. A tabulation comparing Gyromitra and Pseudorhizina is presented. It is also emphasized that, as previously suggested by the author, the genera Discina (Fr.) Fr. and Neogyromitra Imai should be included in Gyromitra, together forming a subgenus of their own, Gyromitra subg. Discina. Gyromitra gigas sensu McKnight is considered different from the true G. gigas, and is described as a new species, Gyromitra montana Harmaja. Seven new combinations, necessary due to the amendments of the two genera, are made: Gyromitra subgenus Discina (Fr.) Harmaja, Gyromitra apiculatula. (McKn.) Harmaja, Gyromitra korfii (Raitv.) Harmaja, Gyromitra macrospora (Bub.) Harmaja, Gyromitra olympiana (Kan.) Harmaja, Gyromitra warnei (Peck) Harmaja and Pseudorhizina californica (Phill.) Harmaja.
Abstract: In the laboratory, decaying wood produces measurable quantities of carbon monoxide as measured with on infra-red gas analyzer. The highest CO ooncentration 205 ppm, was obtained from birch wood, colonized by Piptoporus betulinus. Pure cultures of wood-decomposing fungi grown on malt agar give a positive reaction with palladium chloride. The tolerance of 32 wood-decomposing species of Hymenomycetes was determined by growing them in desiccators, into which measured amounts of carbon monoxide were added. All species proved to grow well in 1:1 CO – air mixtures and most of them grew in 3:1 mixtures, suggesting that in the ecology of wood-decomposing fungi CO is of minor importance.
Abstract: Lentinus lepideus is common on Finnish railway sleepers made of pine wood. Of the 280 railway stations studied, its fruit bodies were observed at 156 stations, which were fairly evenly distributed over the railway net. There is some concentration on less used and poorly maintained lines. Railway age and station size have little influence. During the observation period of five years no yearly differences in the occurrence were noted. Fruit bodies emerge at the end of June, and their number remains almost constant up to September.
Abstract: “The external appearance of 120 single-spore isolates from a basidiocarp of Armillariella mellea was characterized by abundant white raised aerial mycelium, and differed markedly from that of the majority of a number of other isolates made from rhizomorphs and basidiocarps collected in nature. These had dark crustose areas and were generally without aerial mycelium. Both types of mycelia lacked clamp connections. Their appearance did not change during two years’ cultivation. Crustose mycelia were obtained by pairing single-spore isolates. The pairing reaction followed a tetrapolar pattern. Both types of mycelia had only one nucleus in the terminal cells of the hyphae. In older parts of the mycelium, especially in rhizomorphs, the number of nuclei per cell often exceeded 10. In basidiocarps collected in nature, distinctly dicaryotic and clamped hyphae were met with, especially at the bases of basidia.
Various explanations are suggested for the monocaryotic condition of the hyphal tips. As hyphal tip isolations from crustose mycelia obtained by pairing single-spore isolates, regularly gave only crustose mycelia, it is possible that the nuclei in the tips of the hyphae area diploid.”
Abstract: “The material (c. 2800 samples) for this study was collected from planted grassland or the borders of fields throughout the conutry in 1966- 1970. Rhynchosporium orthosporum Caldwell was observed to occur commonly on cultivated and wild grasses in many localities from Helsinki to Lapland. Spores of the fungus were most abundant in the leaves of the grass in early spring and were least abundant in mid summer.
R. orthosporum was the most common causer of leaf spot diseases on Dactylis glomerata L., during the growing season and in part also under the snow. It was also common on Alopecurus pratensis L., especially towards the beginning of the growing season. R. orthosporum also occurred commonly on Phleum pratense L., Festuca pratensis Huds., Lolium perenne L ., Poa pratensis L. and Festuca rubra L. On these grasses the significance of R. orthosporum was smaller than on the grasses first mentioned.
In addition native spores of R. orthosporum were found sporadically on the following species of grass: Agrostis stolonifera L., A. tenuis Sibth., Alopecurus geniculatus L., Calamagrostis arundinaceae (L.) Roth., C. epigeios (L.) Roth., Deschampsia caespitosa (L.) PB., Lolium multiflorum Lam. and Poa annua L. Rhynchosporium secalis (Oud.) Davis was observed rather commonly on Agropyron repens (L.) PB. and sporadically on Bromus inermis Leyss.”
Abstract: “This paper is part of a larger study of the fungi causing leaf-spot diseases on the grasses in leys in Finland. The material examined consisted of grasses growing on cultivated grassland or in the borders of fields. The fresh material (c. 3770 samples) was collected throughout the country, but chiefly from the Viikki Experiment Farm of Helsinki University, from 1966 to 1970. Conidia produced in natural infestations were examined microscopically. The fungi have not been grown in pure culture.
Conidia of the fungi were found on the growing leaves of grasses during the period between early spring (March) and late autumn (November). They occurred rather commonly but in small numbers; mostly only single spores of fungi were found. The aquatic Hyphomycetes live as saprophytic fungi on grasses, and are of negligible importance.
Four species of the aquatic Hyphomycetes were identified on 14 grass species. The most common species was Volucrispora graminea (Haskins) Ingold, McDougall & Dann. Tricellula aquatica Webster occurred rather commonly, but in small numbers. Varicosporium elodeae Kegel was found on two samples of Phleum pratense L . and Tetracladium maxilliformis (Rostrup) Ingold on one of Dactylis glomerata L.”
Abstract: “The material (c. 3770 samples) for this study was collected from planted grasslands or the borders of fields throughout· the country in 1966-1970. Collections of the Plant Pathology Department of Helsinki University were also examined. Spermospora ciliata (Sprague) Deighton was found on 58 grass samples involving 11 grass species, most often on Festuca rubra L., from several localities ranging from Helsinki to Lapland.
Scolecotrichum graminis Fuckel was found on 28 grass samples involving 7 grass species, most often on Phleum pratense L., from southern Finland.”
Abstract: Suspensions of Armillariella spores were forced through fresh cross sections of wood at a maximum pressure of 0.05 atm. Great variations in the degree of spore penetration were found between different tree species. The wood of ring-porous species allowed the spores to flow readily through 16 em thick pieces; in diffuse- pored trees the penetration as considerably smaller, and a 1 em thick piece of conifer wood completely filtered off all the fungus spores. It is concluded that the anatomical structure of wood, in connection with physical phenomena at the wood surface (capillary action, changes in temperature and air pressure, rain splash), may be responsible for differences in the infection process of wood of different tree species.