Chromosome numbers of 23 species (including subspecies) of Hieracium s. str. from the Western Carpathians are presented. First chromosome numbers are reported for Hieracium kuekenthalianum (= H. tephrosoma, 2n = 36), H. praecurrens (2n = 27) and H. virgicaule (2n = 27); first counts from the Western Carpathians are given for H. atratum (2n = 27), H. bifidum (2n = 27, 36), H. carpathicum (2n = 36), H. inuloides (2n = 27), H. jurassicum (2n = 27), H. macilentum (= H. epimedium, 2n = 27), H. nigritum (2n = 36), H. pilosum (= H. morisianum, 2n = 27) and H. silesiacum (2n = 36). New ploidy level (tetraploid, 2n = 36) is reported for H. bupleuroides, hitherto published counts refer only to triploids (2n = 27). Previously published chromosome numbers were confirmed for several other species, i.e. H. alpinum (s.str., 2n = 27), H. bupleuroides (2n = 27), H. crassipedipilum (H. fritzei group, 2n = 27, 36), H. lachenalii (2n = 27), H. murorum (2n = 27), H. prenanthoides (2n = 27), H. racemosum (2n = 27), H. sabaudum (2n = 27), H. slovacum (H. fritzei group, 2n = 36), and H. umbellatum (2n = 18). Triploids and tetraploids predominate, diploids (2n = 18) were found in H. umbellatum. A comprehensive list of previously published chromosome numbers in Hieracium s. str. from the Western Carpathians is provided.
Diurnal fluctuations in the contents of malate in gametophores of Polytrichum commune Hedw. and Polytrichum piliferum Hedw. were small. In gametophores of Mnium undulatum Hedw. and leaves of Hieracium pilosella L. significant differences were found in the accumulation of malate between day and night. However, no significant diurnal differences were found in the contents of citrate. High irradiance, desiccation, and submergence by water resulted in increases in daily fluctuations of malate, particularly in the gametophores of P. piliferum and leaves of H. pilosella. Accumulation of malate during night may show the adaptation of the studied species to unfavourable conditions caused by stresses. The change in activity of NADP-malic enzyme may characterize a response to stress factors. and A. Rzepka, G. Rut, J. Krupa.
Aphis hieracii Schrank (apterous and alate viviparous female, ovipara, male) is defined, along with description of three new species: A. heiei sp. n. (apt. and al; viv. fem.) on Hieracium umbellatum from Denmark, A. curtiseta sp. n. (apt. viv. fem., fundatrix, ovipara and male) on Hieracium (Pilosella) spp. from the Czech Republic, Slovakia, Bulgaria, Moldova and the Ukraine (Crimea), and Aphis mohelnensis sp. n. (apt. and al. viv. fem.) on H. (P.) echioides from the Czech Republic, H. (P.) bauhinii from Bulgaria and H. virosum from Uzbekistan. The latter species differs from A. hieracii in having a long ultimate rostral segment, shorter processus terminalis and, in alate females, more numerous secondary rhinaria. Additonal notes on taxonomy, host plants and distribution of A. hieracii and A. pilosellae are given. Records of Aphis fabae s. lat, and A. frangulae s. lat, on Hieracium spp., are reviewed and a key to the seven species of Aphis on Hieracium is provided.
A taxonomic concept for the Hieracium nigrescens agg. (H. alpinum ≥ H. murorum) in the Western Carpathians is proposed. Three taxa at the species level are recognized, i.e. Hieracium jarzabczynum, H. mlinicae and H. vapenicanum. One new combination, Hieracium mlinicae (Hruby et Zahn) Chrtek f. et Mráz (H. nigrescens subsp. mlinicae Hruby et Zahn) is published. All taxa should be considered as endemic to the Western Carpathians (both the Polish and Slovakian parts). Detailed descriptions, drawings, lists of localities, distribution maps and determination key are provided along with a comparison with the last comprehensive account of the group (by Zahn 1936). Several lectotypes were chosen for the taxa recognized by Zahn within H. nigrescens s.l.
A taxonomic study of the Pilosella alpicola group growing in the Carpathians revealed the presence of two morphologically distinguishable taxa: P. ullepitschii (Błocki) Szeląg and P. rhodopea (Griseb.) Szeląg. While P. ullepitschii is endemic to the Carpathians, P. rhodopea is a Balkan subendemic with two isolated localities in the Southern Carpathians (Mt Cozia and Mt Zmeuretu). The core area of distribution of P. ullepitchii is the natural subalpine and alpine meadows of the Western Carpathians (the Vysoké and Západné Tatry Mts in Slovakia and Poland). In addition, only three isolated localities are known from the Nemira Mts (Romanian Eastern Carpathians) and one from the Bucegi Mts (Romanian Southern Carpathians). Interestingly, the Romanian populations occur in man-made habitats (secondary pastures). Karyological and flow cytometric analyses of 305 plants from 13 populations of P. ullepitschii revealed only diploid plants (2n = 2x = 18). One Carpathian population of P. rhodopea from Mt Cozia is also diploid. This is the first report of diploidy in this species. However, the populations from the main part of the distribution of this taxon in the Balkan mountains include other cytotypes. Detailed morphological descriptions and distributions for both taxa are given.