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The contribution presents phytosociological analyses of the savanna vegetation of Yaguaramas belonging to the classCuratello-Byrsonimetea Borhidi 1979. According to the plant composition, the plant communities under study belong to the orderByrsonimo crassifoliae-Andropogonetalia teneris Bal.-Tul. ordo nov., where two alliances were distinguished, namely theGuillemineo brittonii-Aristidion refractae Bal.-Tul. all. nov. and theByrsonimo crassifoliae-Andropogonion teneris Bal.-Tul. all. nov. The associationsSclerio interruptae-Rhynchosporetum subimberbis Bal. Tul. ass. nov., andPolygalo omissae-Andropogonetum diodontis Bal.-Tul. ass. nov. (both endemic) were classified in the former alliance while the associationByrsonimo crassifoliae-Andropogonetum teneris Bal.-Tul. ass. nov. is a representative of the latter. The following subassociations were distinguished: theSclerio interruptae-Rhynchosporetum subimberbis utricularietosum fimbriatae Bal.-Tul. subass. nov., theByrsonimo crassifoliae-Andropogonetum teneris typicum Bal.-Tul. subass. nov., and theByrsonimo-Andropogonetum sclerietosum interruptae Bal.-Tul. subass. nov.

Die Arbeit beschreibt die synsystematische Stellung und die primären Standortsfaktoren der xerothermen Staudengesellschaften im Wallis und in angrenzender Waadt (Schweizer Zentral-Alpen). Diese Gesellschaften sind alsBrachypodio pinnati-Geranion sanguinei Tx. inMüller 1962 emvan Gils etKozłowska 1977,Brachypodietalia Korneck 1974 undFestuco-Brometea Br.-Bl. etTx. 1943 klassifiziert.

Sectional taxonomy ofTaraxacum in steppe or subsaline habitats in Central Asia is revised based on material collected during expeditions, cultivated or studied in herbarium. Two new sections are described from that area:T. sect.Stenoloba similar toT. sect.Leucantha (syn.:T. sect.Sinensia), andT. sect.Suavia allied toT. sect.Dissecta. The type species of the sectionSuavia is described asTaraxacum formosissimum Kirschner etŠtěpánek. Widespread mountain dandelions of the Caucasus, intermediate between the sect.Piesis andT. stevenii, are described asT. sect.Confusa. Taraxacum species dominating dry habitats in S Ukraine and Crimea are described asT. sect.Borysthenica. Species belonging to the new sections were found to be polyploid and agamospermous.

Folia Geobot. Phytotax., Praha, 20: 397–406.—The percentage of diploids and polyploids in plant communities of WSW Iceland is discussed in connection with environmental conditions, life forms and species diversity. No correlation was found between the age of species and their ploidy. Three basic landscape units are defined.

During 1977 to 1980 the course of flowering and pollen quality were investigated inSalix cinerea, S. fragilis, andS. pentandra, the dominant woody species in a wetland area called “Mokré louky” near Třeboň, South Bohemia, Czechoslovakia. Results were compared with basíc climatological data, and decisive factors of flowering were estimated. BothS. cinerea andS. pentandra produced morphologically well developed pollen with a high degree of viability. Comparison in twelve habitats showed that the pollen ofS. fragilis was very sensitive to climatic factors, and that the marsh habitat “Mokré Louky” was hostile to the generative reproduction of this species. Optimal conditions for pollen germination in vitro were defined for all the three willows.

A new species, Xanthoria tendraensis (Teloschistales, Lecanoromycetes), is described from species-poor lichen communities on shell dunes of the Tendra Spit (northern Black Sea coast, Ukraine), based both on morphological and molecular data. This lichen is similar to X. ectaneoides but differs in having longer ascospores with thicker walls at the poles. A new lichen association, Xanthorietum tendraensis, is described from stable grey dunes. Its characteristic species are Lecania sylvestris s. lat., Polyozosia perpruinosa, Scythioria phlogina and X. tendraensis. The species composition of the new association is similar to communities of Aspicilion contortae (Verrucarietea nigrescentis). Six new sequences of nrITS region were obtained for Xanthoria tendraensis, Xanthocarpia fulva s. lat. and Trebouxia crenulata, which was identified as a photobiont of X. tendraensis.