Folia Geobotanica

Alves, Ruy

doi: 10.1007/BF02807775pmid: N/A

The method and preliminary results of a simple morphoanatomical survey combined with field studies of the populations as some species ofVellozia from Brazil are presented and briefly discussed.

Pyšek, Petr; Křísa, Bohdan; Krhovský, Jan; Vosátka, Miroslav; Olsvig-Whittaker, Linda

doi: 10.1007/BF02807782pmid: N/A

Herben, Tomáš; Skála, Zdeněk

doi: 10.1007/BF02807772pmid: N/A

Krahulec, František; Lepš, Jan

doi: 10.1007/BF02807773pmid: N/A

The set of 25 aquatic and shoreline species which immigrated to the new reservoir Rozkoš during the 21 years after its creation were analyzed with respect to their time of immigration, distance of nearest source localities, life form, seed size, and reproductive system. The reservoir consists of two parts, one with fluctuating and the other with stabilized water level. The immigrating species originated from various distances, from nearby to more than 100 km away. A distance of tens of kilometers can be overcome by many shoreline species, provided that suitable (low competition) habitats are available. The survival time was correlated with the reproductive system: species with autogamic or vegetative reproduction survived longer. Establishment was more successful under a fluctuating water level, which decreased the competitive exclusion of immigrated species by helophytes.

Kirschner, J.; Ŝtêpánek, J.; Tichý, M.; Krahulcovà, A.; Kirshnerová, L.; Pellar, L.

doi: 10.1007/BF02807777pmid: N/A

Allozyme techniques, karyotype analyses and cultivation experiments were carried out on 20 population samples ofTaraxacum sect.Piesis (Compositae), viz.T. bessarabicum (17 samples from W. and C. Europe, Ukraine and Crimea, Central Asia and the Altai),T. salsum from Crimea,T. x mesohalobium from Crimea, andT. stenolepium from the Causasus. The taxa studied share a primitive, symmetrical karyotype. All taxa studied are sexual,T. bessarabicum mostly autogamous. Sexuality at the tetraploid level (T. stenolepium) and occasional male sterility in a sexual (T. bessarabicum in Moravia) were recorded for the first time in the genus. Selfing, diploidy and the highly predictable habitat may account for the mostly low level within population allozyme variation inT. bessarabicum. W. and C. European samples ofT. bessarabicum are almost invariable allozymically and, as a group, have no unique alleles. The Crimean and Asian group of populations shows higher levels of allozyme variation and has 15 alleles not found in the former group at 13 loci studied. Recent migration from one source region is suggested to account for the homogeneity of the western group, refugial persistence of alleles and possible introgression from sympatric species may have resulted in allele richness in the eastern group. Hybridization betweenT. bessarabicum andT. salsum was documented by allozyme patterns in a few plants in Crimea. Some aberrant allozyme or karyotypic features of two populations are discussed as well.

jun, Jindřich

doi: 10.1007/BF02807780pmid: N/A

Chromosome numbers are given of 15 species of the genusHieracium L. s. str., representing seven species groups (in the sense of Flora Europaea, roughly corresponding to Zahn's “species principales”) from the Krkonoše Mts., N. Bohemia and SW Poland. For the first time chromosome numbers are reported forH. melanocephalum Tausch (2n=27),H. tubulosum Tausch (2n=36),H. schustleri Zlatník (2n=36),H. fritzei F. Schultz (2n=27),H. rohlenae Zlatník (2n=27),H. nigrescens Willd. (2n=36),H. decipiens Tausch (2n=36),H. atrellum Juxip inSchischkin etBobrov (2n=27),H. subnigrescens (Fries exNorrlin)Dahlst. (2n=36),H. sudeticum Sternberg (2n=36),H. pedunculare Tausch (2n=36),H. glandulosodentatum Uechtr. (2n=36),H. wimmeri Uechtr. (2n=27). InHieracium alpinum L. s. str. the number 2n=27 has been confirmed. The results show a high proportion of tetraploid taxa; no diploids have been found.

Krahulcová, Anna

doi: 10.1007/BF02807779pmid: N/A

Chromosome numbers were determined inGeum montanum, L.: only hexaploids (2n=42) were found on 44 localities throughout most of the distribution area. Tetraploid level (2n=28) previously reported in this species from the Carpathians was not confirmed.

Golub, V.

doi: 10.1007/BF02807774pmid: N/A

Higher syntaxa of the classAsteretea tripolium are reviewed. This class covers plant communities of the Euro-Asian continent on low- and medium-salinized soils with medium moisture conditions where perennial herbaceous plants (hemicryptophytes) of non-succulent character prevail. On the territory of the former USSR and Mongolia, the classAsteretea tripolium is represented by the following orders:Glauco-Puccinellietalia Beeftink etWesthoff inBeeftink 1962,Cirsietalia esculenti Mirkin etV. Golub exV. Golub ord. novus,Scorzonero-Juncetalia gerardii Vicherek 1973,Halerpestetalia Mirkin et al. exV. Golub ord. novus,Artemisio santonicae-Limonietalia gmelinii V. Golub etV. Solomakha 1988,Suaedetalia corniculatae V. Golub ord. novus. Superspecies and aggregations of species are used for the diagnosis of higher syntaxa.

Prach, Karel

doi: 10.1007/BF02807778pmid: N/A

Zrzavý, Jan

doi: 10.1007/BF02807776pmid: N/A