UDK 582.632.2:581.9(497.6) In this paper is given an overview of the rare occurrence of beech with oaklike bark (Fagus sylvatica var. quercodies) in Bosnia and Herzegovina, which is recorded for the first time by Karlo Malý in 1934. In addition to basic information about the distribution of this taxon we gave a detailed description of a one its remarkable recent tree from Kreševo area. These unusual phenomena induce scientific interest and require special protection and conservation actions.

Abstract The Buffelgrass (Cenchrus ciliaris L., Poaceae) is one of the most important pasturage grasses due to its high productivity and good forage qualities. This species possess a high adaptability to bioclimatic constraints of arid zones and may be used for the restoration of degraded arid ecosystems. Tunisian populations present three ploidy levels (4x, 5x and 6x) with a basic chromosome number x=9. This study reported for the first time the distribution of the ribosomal genes (rRNA) for pentaploid and hexaploid cytotypes of Cenchrus ciliaris. Molecular cytogenetic study using double fluorescence in situ hybridization has shown that the two rDNA families, 5S and 18S-5.8S-26S (18S), displayed intraspecific variation in number of loci among different ploidy levels. Each ploidy level was characterized by specific number of both 5S and 18S rDNA loci (two loci in tetraploid, five in pentaploid and six in hexaploid level). For three studied cytotypes (4x, 5x and 6x) all 5S rDNA loci were localized on the subcentromeric region of chromosomes, while 18S loci were situated on the telomeric region of short chromosome arms. Data of the FISH experiments show proportional increase of ribosomal loci number during polyploidization processes.

A revision of the genus Gymnospermium (Berberidaceae) in the Balkan Peninsula is carried out. Three species are recognised. Gymnospermium maloi is described as a new species from Mt. Picari in Gjirokastra district, southern Albania. It is compared with the closely related G. scipetarum which has a different habitat and distribution in central Albania and southern Montenegro. The chromosome number and karyotype features of G. maloi are provided for the first time. The chromosome formula of 2n = 2x = 14 (1 metacentric, 1 meta-submetacentric and 5 submetacentric chromosome pairs) is unusual as 2n = 16 has been reported for other members of the genus. The nuclear DNA content (2C-value) of all three species was determined. The genome size of G. maloi is 29.44 (+/- 0.47) pg, for G. scipetarum (chromosome number still unknown) 29.55 (+/- 1.35) pg, and for G. peloponnesiacum (2n = 2x = 16) 31.93 (+/- 2.38) pg. These values are the first genome size measurements for the genus. All three species are mapped and fully illustrated. A key to the European species is also presented.

Genus Artemisia is thought to have reached the Americas across the Bering Strait from Asia during the late Tertiary, but the systematic position of the South American endemic species and the migration routes towards the south have not yet been studied. We used nuclear DNA sequences to unravel the interspecific relationships among the South American Artemisia and their connections with the remaining species of the genus, as well as using fluorescent in situ hybridisation and genome size assessments to characterise this polyploid complex. Most of the species are clustered in a monophyletic clade, nested within the American endemic clade, with the exception of A. magellanica Sch. Bip., which appears segregated from the other American species and constitutes a clade together with A. biennis Willd. Fluorescent in situ hybridisation and genome size data revealed that monoploid genome size remains quite constant across ploidy levels and a proportional increase of ribosomal loci was detected, a dynamic not usually found in this genus. The results are discussed in the light of evolutionary processes which occur in plants, and plausible origins for the South American endemic species are hypothesised.