A new hexaploid species of Centaurea section Acrolophus (Asteraceae) from Evvia Island,Greece

Centaurea carystea Trigas & Constantin., a new yellow‐flowered species of Centaurea from Mt. Ochi on Evvia Island (Greece), is described and illustrated. It is a member of the polymorphic C. section Acrolophus and allied to taxa of the C. attica aggregate, C. pelia and C. mantoudii. The new species appears to be a local and threatened endemic, with the total number of individuals known being less than 500. A karyological examination revealed that it is hexaploid, with 2n = 6x = 54, an unusual number in Centaurea, which may indicate a hybrid origin. To further clarify the taxonomic position of C. carystea , we used random amplification of polymorphic DNA markers of 25 plants belonging to nine species, subspecies and varieties morphologically related to the new species, together with two reference taxa. Clustering using the unweighted pair group method with arithmetic mean indicated a discrete position for C. carystea , close to but distinct from the yellow‐flowered C. mantoudii. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 762–774.     

A new species of Achillea (Asteraceae: Anthemideae) from south-east Peloponnisos, Greece

A new species of Achillea L., Achillea occulta Constantin. & Kalpoutz., from the summit area of Mount Koulochera in south-east Peloponnisos, Greece, is described and illustrated. It belongs to A . sect. Ptarmica and further, to a small group of taxa known under the illegitimate sectional name 'Anthemoideae'. In Greece, A. occulta has no close allies. The taxonomically related taxa, i.e. A. barrelieri (Ten.) Sch. Bip., A. mucronulata Bertol., A. oxyloba (DC.) Sch. Bip. and A. schurii Sch. Bip. are found in the Italian Peninsula, the Alps and the Carpathians. Phytogeographically, the finding of a species with such taxonomic connections in south-east Greece was unexpected. The new species grows in semi-shade, often hidden in suitable limestone rock hollows and the foot of rocks, together with several other Greek endemics. Its chromosome number of 2 n  = 18, counted in root tips, is also reported and illustrated.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 147 , 249–256.     

A new species of Centaurea (sect. Phalolepis, Compositae: Cardueae) from eastern Peloponnisos, Greece

A new species of Centaurea L. , Centaurea leonidia Kalpoutz. & Constantin. , from two localities west and south-west of the town of Leonidio in eastern Peloponnisos, Greece, is described and illustrated. It belongs to C . sect. Phalolepis , and taxonomically its closest relatives are C. heldreichii Halácsy , a very localized species from south-west Sterea Ellas (Greece) and, surprisingly, C. niederi Heldr., which belongs to sect. Acrolophus. The new species is currently known from two populations of less than 100 individuals each, growing on almost inaccessible cliffs close to the convent of Agios Nikolaos Sintzas (St. Nicolas of Sintza) and the slopes of Poundes summit. Several other Greek endemic species are found in the same areas. Centaurea leonidia is scientifically important as it belongs to a small group of taxa, which, although they are members of sect. Phalolepis , have close allies in sect. Acrolophus. The chromosome number of C. leonidia , 2 n  = 18, counted in root tips, is also reported and illustrated.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 375–383.     

The rediscovery of Biebersteinia orphanidis Boiss. (Geraniaceae) in Greece

Biebersteinia orphanidis was considered extinct from Greece and Europe as it had not been collected since Orphanides' type collection of 1851. Its rediscovery is reported here from a mountain close to the classical locality. The species serves as a distinct phytogeographical link between the floras of Greece and Anatolia. In Greece, at least, it grows in a critically low number of individuals. Data on the species habitat and population status are given, and potential threats to its survival are discussed.     

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.