Article

A criticai taxonomic revision of seven species from sect. Napulifera of genus Cyanus - Cyanus pseudoaxillaris, C. orbelicus, C. velenovskyi. C. napuliferus, C. nyssanus, C. tuberosus and C. thirkei has been made. For each species descriptions of the overall morphology, pollen grains and karyotype as well as the distribution area are given. Cyanus tuberosus is recorded for the first time for Greece. It has been established that C. nyssanus, so far considered the most wideIy distributed species within the group, is in fact restricted to a small area in Eastem Serbia. The type of hair-covering of leaves has taxonomic value for distinguishing between C. pseudoaxillaris and C. thirkei. The pollen morphology ofall species is of Montana-type (Wagenitz 1955). Pollen features support the species taxonomic rank of C. pseudoaxillaris and C. tuberosus. Two basic chromosome numbers, x = 11 and x = 10, have been found which show good correlation with the pollen features. Cyanus tuberosus is tetraploid. One 8-chromosome has been observed in the karyotype of C. thirkei. The main evolutionary mechanisms in the group are discussed ..