Kitaibelia vol. 18 – no. 1-2. (2013) p.129-135.
A Riccietum rhenanae Knapp et Stoffers 1962 előfordulása Magyarországon
Csiky János – Csikyné Radnai Éva – Purger Dragica
Four new occurrences of Riccia rhenana Lorbeer in K. Müll., a rare, cryptogenic and endangered (EN) aquatic liverwort species, as well as the first report on Riccietum rhenanae Knapp et Stoffers 1962 in Hungary are presented in this paper. Since all the collected specimens were terrestrial thalli, R. rhenana was mentioned as a Nanocyperion species in former Hungarian studies. Although both of R. rhenana and R. fluitans prefer eutrophic water bodies, the optimum of R. rhenana is in eu- or hypertrophic, shallow ponds and pools that warm up rapidly. According to literature the species poor stands of Riccietum rhenanae occur in more eutrophic, polluted and warmer water bodies than Riccietum fluitantis. All of the four new stands of Riccietum rhenanae are partially shaded by trees or shrubs. Two stands of the Hungarian R. rhenana population were found in very different water bodies, that refers to a wide range of its tolerance for salinity (EC: 98 μS/cm and 1168 μS/cm). In Hungary, R. rhenana is supposed to be more distributed in lowland and colline areas, than it was revealed in earlier studies.