Ploidy levels in some European representatives of the Suaeda maritima group

Chromosome numbers are given for three species of the Suaeda maritima group, differentiated into three ploidy levels: diploid Suaeda prostrata Pallas (2n = 2x = 18), tetraploid Suaeda maritima (L.) Dumort. (2n = 4x = 36) and octoploid Suaeda pannonica (Beck) Graebn. (2n = 8x = 72). The plants studied were collected in the Pannonian region of Europe; in addition, S. maritima s. str. also originated from three other European localities. Octoploidy, revealed in S. pannonica for the first time, is the highest ploidy level found in the genus in Europe. The genus Suaeda, comprised predominantly of annuals, displays a wide variation in ploidy levels (up to 10x), as is illustrated here by literature data. The importance of polyploidy in evolution of annual taxa is briefly discussed.