Karyotaxonomy of Greek serpentine angiosperms

The chromosome numbers are given for 20 angiosperm taxa, most of which grow predominately or exclusively on serpentine in Greece, and the karyotype morphology is illustrated in all cases but one. Chromosome data are provided for the first time for ten taxa ( Alyssum pogonocarpum, Centaurea charrellii, C. vlachorum, Cephalaria fanourii, Matricaria tempskyana, Onosma stridii, Scorzonera doriae, Silene fabarioides, S. salamandra, Trinia glauca ssp. pindica ) and for the endemic monospecific genus Leptoplax . A new number is reported for Thymus teucrioides ssp. candilicus . An unexpected dysploid number is recorded for a population of Leontodon hispidus ssp. hispidus. Chromosome number and karyotype details from Greek populations are presented for the rest of the taxa. Chromosomal evidence supports close relationships among members of Onosma subsect. Asterotricha . The unusual chromosome number of Centaurea vlachorum supports its placement either in C. sect. Jacea or C . sect. Cyanus . The evolution of taxa in sections Vierhapperia, Pulvinares , and Nervosae of Scorzonera appears to be connected with particular chromosomal rearrangements and dysploidy. Leptoplax does not share the same chromosome number with Peltaria but with Bornmuellera instead, something that facilitates infrageneric hybridization. Further issues of taxonomy, distribution, evolution and conservation of serpentine species are briefly discussed where appropriate. © 2002 The Linnean Society of London , Botanical Journal of the Linnean Society , 2002, 139 , 109–124.