Contribution to the cytotaxonomical knowledge of four species of Serapias L. (Orchidaceae)

Abstract Serapias L. includes about thirty entities, but just one (S. lingua) is presently known as polyploid. In this paper we reported, for the first time, the chromosome number of S. gregaria, S. olbia and S. strictiflora, three endemic species of Southwest Europe, that resulted tetraploid with 2n = 72 chromosomes as S. lingua. The strong affinity between these four species revealed by molecular phylogenetic studies based on cpDNA is now supported by their common tetraploid level, so that polyploidy can be considered for this genus a possible mechanism of speciation. The karyotype of another endemic species of Iberian Peninsula, S. perezchiscanoi, was carried out in order to add new karyological data on Serapias orchids