Polyploidy is one of the most important evolutionary pathways in flowering plants and has significantly contributed to their diversification and radiation. Due to the prevalence of reticulate evolution spanning three ploidy levels, Knautia is considered one of the taxonomically most intricate groups in the European flora. On the basis of ITS and plastid DNA sequences as well as AFLP fingerprints obtained from 381 populations of almost all species of the genus we asked the following questions. (1) Where and when did the initial diversification in Knautia take place, and how did it proceed further? (2) Did Knautia undergo a similarly recent (Pliocene/Pleistocene) rapid radiation as other genera with similar ecology and overlapping distribution? (3) Did polyploids evolve within the previously recognised diploid groups or rather from hybridisation between groups? The diversification of Knautia was centred in the Eastern Mediterranean. According to our genetic data, the genus originated in the Early Miocene and started to diversify in the Middle Miocene, whereas the onset of radiation of sect. Trichera was in central parts of the Balkan Peninsula, roughly 4 Ma. Extensive spread out of the Balkans started in the Pleistocene about 1.5 Ma. Diversification of sect. Trichera was strongly fostered by polyploidisation, which occurred independently many times. Tetraploids are observed in almost all evolutionary lineages whereas hexaploids are rarer and restricted to a few phylogenetic groups. Whether polyploids originated via autopolyploidy or allopolyploidy is unclear due to the weak genetic separation among species. In spite of the complexity of sect. Trichera, we present nine AFLP-characterised informal species groups, which coincide only partly with former traditional groups. Knautia sect. Trichera is a prime example for rapid diversification, mostly taking place during Pliocene and Pleistocene. Numerous cycles of habitat fragmentation and subsequent reconnections likely promoted hybridisation and polyploidisation. Extensive haplotype sharing and unresolved phylogenetic relationships suggest that these processes occurred rapidly and extensively. Thus, the dynamic polyploid evolution, the lack of crossing barriers within ploidy levels supported by conserved floral morphology, the highly variable leaf morphology and unstable indumentum composition prevent establishing a well-founded taxonomic framework.

The paper proposes eight new nomenclatural combinations and indicates two new synonyms. There are 11 taxa (species and subspecies) of the vascular flora that are new for the flora of Serbia (of which nine are autochthonous and two allochthonous plants). Two autochthonous species were confirmed for the flora of Serbia. Six plant taxa are a novelty for proper Serbia, Vojvodina, or Kosovo and Metohija. There are eight taxa whose presence in Serbia or in its territorial units has been refuted.

Although some widespread, native cow parsnips (Heracleum L. spp., Apiaceae) had broad medicinal and culinary applications throughout history, the knowledge about their volatile constituents is insufficient. This work investigates the composition and bioactivities of H. sphondylium L. (HSPH), H. sibiricum L. (HSIB) and H. montanum Schleich. ex Gaudin (HMON) essential oils. The composition was tested by GC and GC-MS. (Z)-β-Ocimene was the most abundant in HSPH (28.9%) and HMON (20.4%) root oils, while in HSIB root oil, β-pinene (26.2%), methyl eugenol (22.3%) and elemicin (25.6%) prevailed. Leaf and flower oils were dominated by various sesquiterpenes (germacrene D, β-sesquiphellandrene, (E)-β-farnesene and/or (E)-caryophyllene) and/or phenylpropanoids (apiole, methyl eugenol, elemicin and/or (Z)-isoelemicin). Octyl acetate (57.5–67.1%) was the main constituent of all fruit oils. The antimicrobial activity was screened by a microdilution method against eight bacteria and eight fungi. The strongest antimicrobial effect, in several cases better than the activity of antibiotics, was shown by HSPH (MICs = 0.12–3.30 mg mL⁻¹) and HMON (MICs = 0.10–1.30 mg mL⁻¹) flower oils against bacteria, and HSIB fruit oil against fungi (MICs = 0.15–0.40 mg mL⁻¹). The MTT test revealed that the oils were not or weakly cytotoxic against human malignant HeLa, LS174 and/or A549 cells (except HSPH root oil; IC₅₀ = 5.72–24.31 μg mL⁻¹) and that tested oils were not toxic against human normal MRC-5 cells (at 200.00 μg mL⁻¹). Significant activity observed against microorganisms that are the common cause of foodborne diseases, food contamination and/or hospital-acquired infections justifies certain traditional uses of the investigated plants and represents a good basis for further research of these Heracleum oils.

The paper presents three new nomenclature combinations related to representatives of the orchid family. In addition, 14 taxa (species, subspecies and hybrids) of vascular flora which are newly registered for Serbia (of which 8 are autochthonous and 6 allochtonous plants) are presented. A confirmation of old or unreliable literature records for four autochthonous and one allochthonous plant in the flora of Serbia has been done. Four plant taxa are a novelty for proper Serbia, Vojvodina, or Kosovo and Metohija, and for 7 plants, presence in certain administrative units in Serbia has been confirmed. In the last part of the paper, there is a review of 9 disputed taxa for our country.

The paper propose nine new nomenclature combinations and indicate eight new synonyms. There are 12 taxa (species and subspecies) of vascular flora which are new for the flora of Serbia (of which nine are autochthonous and three 88 N iketić, M. etal. : Annotated Checklist of Vascular Flora of Serbia II allochtonous plants). An old or unreliable literature records for three autochthonous and one allochthonous plant in the flora of Serbia has been confirmed. Eight plant taxa are a novelty for proper Serbia, Vojvodina, or Kosovo and Metohija, and for three plants, presence in certain administrative units in Serbia has been proved. The last part of the paper contains information on eight taxa whose presence in Serbia or in its territorial units has been refuted.