CYTOTAXONOMIC STUDIES IN THE TRIBE CYNAREAE (COMPOSITAE)

Abstract

Chromosome numbers of 40 taxa of nine genera of the Cynareae together with discussions of pertinent taxonomic problems are presented. Chromosome counts for 26 taxa are presented for the first time; the chief of these are: Carduus cernuus, n = 11; C. pycnocephalus and C. tenuiflorus, 2n = 54; Cirsium arachnoideum, C. obvallatum, C. pendulum, C. tricholoma, 2n = 34; Echinops (six species), 2n = 30; Notobasis syriaca, 2n = 34; Onopordum (two species), 2n = 34; Saussurea densa, 2n = 26; Silybum eburneum, n = 17. The morphology of the chromosome complements is discussed in relation to the interrelationships and phylogeny of these genera. Cytological evidence supports the retention of Notobasis and Chamaepeuce as distinct from Cirsium.