B. Papp szerk.: Studia Botanica Hungarica 36. 2005 (Budapest, 2005)

Buczkó, Krisztina; Wojtal, A.: Moss inhabiting siliceous algae from Hungarian peat bogs

ries (see also Table 1). Hantzschia elongata, Kobayasiella subtilissima and Eunotia meisten are among the "endangered taxa". Encyonema mesiana, Eunotia paludosa, E. cf. praerupta and E. rhomboidea are "vulnerable", Fragilaria capucina var. amphicephala falls in the "low risk" category, while Fragilaria tenera and F. virescens are "presumably endangered". Chamaepinnularia soehrensis formerly belonged to Navicula, and only one occurrence is documented from Hungary, although what we present is a different variety. CHOLNOKY (1933) has found Navicula soehrensis var. capitata Krasske in a spring close to the Danube more than 70 years ago. NÉMETH (2005) has not listed it at all. In the present study 2 forms of Chamaepinnularia soehrensis (differing from var. capitata) are distinguished (Table 1). As one conclusion, we may state that this is a very rare species in Hungary. Otherwise - naturally NÉMETH'

s paper (2005) does not deal with the new records, which we publish here - probably these new occurrences must be referring to rare diatoms in the Hungarian flora. To summarise the above, according to the rare, new and threatened diatoms, altogether 18 taxa (more than 19% of the total flora) are of conservation concern and require special attention in the studied mires. The significance of aerophytic diatoms within the entire vegetation can not be neglected, with the mass appearance of stomatocysts they are among the markers of drying up the mires. It is among the most surprising results of the study that the diatom flora of the "large" Hungarian bogs, Kis-Mohos-tó and Nagy-Mohos-tó, is very poor. Apparently, undisturbed and extensive habitats in this area do not support diversified diatom assemblages, the species number is limited and their abundance is very low. In Nagy-Mohos-tó, Lemnicola hungarica, a recently expanding diatom was recorded on Sphagnum angustifolium. Further developing of sampling strategy and more studies are planned for the verification of presence and dynamics of siliceous algae on mosses and to collect more algological data from other localities within KisMohos-tó and Nagy-Mohos-tó. We feel urgency in a better documentation (LM and SEM) of the diatom flora of Hungary, especially in accordance with the trends of European standards (Water Framework Directives) which draw special attention to mires. * * * Acknowledgements - The study was supported by the Hungarian Scientific Research Fund (OTKA T 43078). The cooperation between the Hungarian and Polish Scientific Academies provided the opportunity of personal consultation between the authors. Special thanks are due to Erzsébet Szurdoki for her invaluable help and István Rácz for the linguistic correction.