Cytogenetic Studies in Cochlearia L. The chromosomal homogeneity within both the 2n = 12 diploids and the 2n = 14 diploids and the cytogenetic relationship between the two chromosome levels

A cytogenetic study has been carried out within the diploid Cochleariae. This has demonstrated that all the 2n = 12 taxa are chromosomally homogeneous, as are those with 2n = 14. It is therefore suggested that the 2n = 12 group be recognised as C pyrenaica DC, with the morphologically distinct specimens from France and Spain at present regarded as C. aestuaria (Lloyd) Heywood being given subspecific rank in C. pyrenaica. It is also suggested that all the 2n = 14 taxa be regarded as C groenlandica L. Some doubt is expressed on the existence of C. scotica Druce as a species, as all the specimens of this taxon examined proved to be tetraploid with 2n = 24. Genomic analysis has shown that the 2n = 14 group is a primary tetrasomic derivative of the 2n = 12 group.