Medium-Joining Network ( A ) and unrooted NJ tree ( B ) of 26 cpDNA haplotypes (H1-26) across the N Hemisphere populations of the diploid and polyploid taxa of A. millefolium agg. The data are based on sequences of two cpDNA noncoding regions, trnH-psbA and trnC-ycf6. Short bars on branches of the network indicate the number of variable sites (incl. gap polymorphisms, see Table 2). Red numbers next to the branches of the NJ tree are bootstrap values. Plant individuals are labelled as "taxa abbreviation (population code-individual identity No.)". For taxa abbreviations, see Table 1.