Доклади на Българската академия на науките Comptes rendus de l’Acad´ emie bulgare des Sciences Tome 67, No 5, 2014 BIOLOGIE Botanique A NEW ALIEN SPECIES OF CLEMATIS (RANUNCULACEAE) TO THE BULGARIAN FLORA Vladimir Vladimirov, Antoaneta S. Petrova * , Jerzy Zieli´ nski ** (Submitted by Academician V. Golemansky on February 2, 2014 ) Abstract A new alien species to the Bulgarian flora is reported: Clematis tibetana (Ranunculaceae) which is native to Asia. In Bulgaria it has been recorded in the Black Sea Coast (Northern) floristic region and should be considered recently naturalised in the Bulgarian flora. The main distinguishing morpho- logical characters of the taxon, its chromosome number (2n =4x = 32), and some notes about the habitat and population are presented. Key words: alien plants, Bulgaria, Clematis tibetana, naturalised plants, Ranunculaceae, vascular plants Introduction. Recent studies on the alien species in the Bulgarian flora resulted in the discovery of numerous new taxa for the country [ 1–5 ]. Particular attention has been paid to the alien flora along railways and roads, especially in close proximity to border passes and international ports. This paper reports one more species – Clematis tibetana which was discovered along a railway near Razdelna village, in the Black Sea Coast floristic region. In flowering and fruiting stage the species is an exceptional beauty and certainly deserves cultivation as an ornamental shrub. Material and methods. Plant material was collected by the first two authors along a railway track. Morphological characteristics were noted from the material gathered and compared with data from literature [ 6, 7 ]. Nomenclature and taxonomy of all other species mentioned in the text follow Delipavlov and Cheshmedzhiev [ 8 ]. Financial support of the Bulgarian Science Fund under project DO-02-194 is gratefully acknowledged. 671