GENETIC DIFFERENTIATION OF CAREX-FLAVA AND CAREX-VIRIDULA IN WEST EUROPE (CYPERACEAE)

Recent systematic treatments evaluating variation in the Carex flava species complex have divided the West European representatives into two species, C. flava and C. viridula. These treatments contrast with previous reports that have recognized as many as nine species based upon morphological variation. To assess the systematic relationship of C. flava and C. viridula, allozyme analyses were conducted on 34 West European populations distributed from the Alps to the Arctic Circle. Data were obtained from electrophoresis of soluble enzymatic proteins extracted from leaf tissue. Fifteen of the 20 presumptive loci examined for this study were found to be polymorphic; variation was distributed between the two species and within 25 populations. These data support recognition of C. flava as a species distinct from C. viridula at a genetic identity of 0.69. The two species are discriminated by diagnostic alleles at two loci and highly disparate allele frequencies at an additional five loci. There is little genetic differentiation among populations of C. flava in West Europe. Genetic identities exceeding 0.95, which were obtained from infraspecific pairwise comparisons of C. flava, do not support recognition of subspecies. In contrast, C. viridula was highly differentiated with a G(ST) of 0.806 strongly supporting recognition of subspecies.