Canopy fungi (terrestrial aquatic hyphomycetes) from twigs of living evergreen and deciduous trees in Hungary

Twigs from deciduous and coniferous living trees in Hungary were cut, incubated and examined selectively for the presence of a group of canopy fungi, the so-called terrestrial aquatic hyphomycetes. Underwater incubation supplemented with aeration (the traditional method for aquatic hyphomycetes) was applied to observe sporulation in canopy fungi. Water was membrane-filtered and fungal elements trapped on the filters were stained and examined microscopically. Additionally the surface of the twigs was scraped for detection of sporulating structures. In total, 32 fungal species were detected on the twigs, 13 are described, a further 11 are identified to genus and eight are of unknown affinities. Two species, Retiarius bovicornutus and Tripospermum myrti, occurred on all tree species. The conidia of R. bovicornutus occurred in 85.2% of the samples but with greatly differring frequencies, with a maximum in spring. Conidiophores of R. bovicornutus, Trifurcospora irregularis and Trinacrium subtile were seen on twig surfaces. The numbers of species and conidia were higher on the twigs of evergreen trees than on those of deciduous trees. The greatest similarities in species composition were obtained between trees growing near each other. The highest indices of similarity (78.1; 55.4) occurred between Chamaecyparis and Juniperus. Fungal species composition on deciduous twigs after exposure in a stream from earlier studies and after incubation in distilled water are compared and discussed.