Seven Turkish species of Nonea Medik. (Boraginaceae-Boragineae) were studied karyologically using material collected in the field from wild populations. Somatic chromosome number and karyotype morphology were determined for each species using orcein staining. Nonea pulmonarioides is diploid with 2n=20, though some cells showed 2n=19. Nonea anchusoides turned out to be tetraploid with 2n=4x=40, while N. macrosperma was characterized by a hexaploid complement of 2n=6x=60. These data indicate polyploidy based on x=10 as a major mechanism of speciation in the perennial members of the genus. Among the annuals, N. echioides and N. versicolor showed 2n=16, while N. obtusifolia and N. lutea were characterized by 2n=20 and 2n=14, respectively. The results reveal that x=10 is more frequent in Nonea than previously realized, and that it may be the ancestral haploid number of diploid endemics of (sub)alpine habitats in the Pontic-Caucasian mountain system. The hypothesis is here proposed that the base numbers x=9, x=8 and x=7, progressively prevalent in the annual species from lower altitudes, may have originated through descending dysploidy associated with the tendency to shorten the life cycle as an adaptation to arid habitats.

Nonea pallens was recently collected by the authors in the Yildiz mountain region in Turkey-in-Europe. The species is new for the Turkish flora and the population marks the southern limit of the species range. Geographical and ecological details are given about the record locality, along with an original description and iconography of the Turkish specimens. Original material of N. pallens was traced in G, W and FI, allowing a lectotype to be selected. Finally, a karyological analysis provided new data about the systematic position of this poorly known species within the genus.

The results of karyological analyses and SEM micromorphological observations on vegetative and reproductive structures of the critical genera Gastrocotyle, Hormuzakia and Phyllocara (Boraginaceae: Boragineae) are presented and discussed in relation to their taxonomic position within the tribe. Each of these monotypic genera is characterized by distinctive features in stigma morphology, papillar pattern, structure of faucal scales, development of the hairy annulus at the base of the corolla tube and ornamentation of the mericarp coat surface. G. hispida and H. aggregata showed 2n = 16 and complements of medium-sized and very large chromosomes, respectively. P. aucheri was characterized by a tetraploid set of 32 chromosomes including a group similar to those of Anchusa and a group closer to those of Nonea in terms of size and centromcric position. This species could have an allopolyploid origin, resulting from the hybridization of members of these two genera. Along with distinctive traits in inflorescence structure, fruit shape and pollen morphology, karyological and micromorphological characters determine sharp phenetic discontinuities from Anchusa, from which these plants should be kept generically separated. At the same time, the presence of relevant autapomorphies in each of the three genera prevents them from being merged in a single genus.