The annotated chromosome numbers of 25 species from 6 families of monocotyledons, most of them (14) belonging to Poaceae family, are presented here. The data, except three chromosome counts (Allium oleraceum from Hungary and Calamagrostis villosa from Slovakia), are all based on plants collected in the Czech Republic. The karyological data of 21 species represents new information. While the majority of species presented here originated from one or two localities each, the species Calamagrostis villosa has been studied more extensively: all plants, collected altogether at 13 localities (mountain and lower altitudes), are characterized by an invariable decaploid level (2n = 70). The record of triploid Allium oleraceum is only the second reference to this rare ploidy level in this species. All original karyological data are compared with literature references to particular species, preferentially from Europe.
Chromosome numbers for 239 plants from 84 localities in the Czech Republic, Slovakia, Hungary, Germany and Poland are given. Most of the populations were pentaploid (2n = 45), while hexaploid (2n = 54) and tetraploid (2n = 36) populations were rarer. A long marker chromosome was observed in plants from 8 pentaploid populations. Tetraploid plants occurred mainly in Slovakia and Hungary. In the Czech Republic and Germany, most populations were pentaploid. Hexaploid populations (2n = 54) were rare but scattered over the entire study area. The co-occurrence of two different cytotypes was documented at 7 sites. Most tetraploids were fully sexual and only a few tetraploid plants from Poland were apomictic; pentaploid and hexaploid plants were apomictic. Two morphotypes of H. bauhini were distinguished: tetraploid and hexaploid plants from Slovakia and Hungary, and some hexaploid plants from the Czech Republic were assigned to the H. magyaricum group, while tetraploids and hexaploids from the Czech Republic and Poland plus all pentaploids belong to the H. bauhini group.
The chromosome numbers of 95 populations of taxa belonging to the Scilla bifolia group growing in the territory of Western Carpathians, and adjacent part of the Pannonian lowland (Slovakia, Hungary, Austria, Czech Republic – Moravia) are presented. Scilla kladnii Schur (41 populations) and S. vindobonensis Speta (18 populations) have only the chromosome number 2n = 18. Both these diploid taxa seem to be karyologically uniform throughout their distribution. For S. drunensis (Speta) Speta subsp. drunensis (2 populations), and S. drunensis subsp. buekkensis (Speta) Kereszty (15 populations) the chromosome number 2n = 36 was found. For S. spetana Kereszty (2 populations), the chromosome number 2n = 54 was confirmed for Hungary and Austria. For two groups of populations of S. drunensis s.l. from Slovakia (14 populations in total) the chromosome number is 2n = 36, which is new information for the Western Carpathians. Apart from tetraploids, hexaploid populations with 2n = 54 were confirmed for three localities in Slovakia and Czech Republic (Moravia). All results are compared with earlier published data.