Karyosystematic study of Potentilla L. subgen. Potentilla (Rosaceae) in the Iberian Peninsula

Chromosome numbers in 80 populations belonging to 18 species of Potentilla L. subgen. Potentilla from the Iberian Peninsula and two of P. maura, a Nor th African endemic taxon, have been counted. The basic number of chromosome s is always x = 7 and these chromosomes are small (between 1 and 2 mu m). F or three species, the number of chromosomes is reported for the first time and, for another six, this number has been established in Iberian represent atives. Moreover, new ploidy levels have been obtained for P. hispanica and P. crantzii with regard to their entire distribution area, and in P. ciner ea and P. neumanniana for the Iberian Peninsula. Some taxonomic, phylogenet ic and phytogeographic comments are made for several species or groups of s pecies from the West Mediterranean region. In 13 species only one ploidy le vel has been found, but six species have several ploidy levels. Seven ploid y levels occur in the investigated taxa. The frequency of each ploidy Bevel represented within Iberian Potentilla is analysed and the data are compare d with those available for taxa from the rest of the distribution area of t he genus. (C) 2000 The Linnean Society of London.