Unrooted Neighbour Joining phylogram of 10 diploid Achillea species (seven of and three outside A . millefolium agg.) based on the SBP gene sequence data. The tree contains 21 SBP haplotypes generated from 163 clones (sequences) from 35 individuals of 19 populations. Bootstrap supports (> 50%) from both methods (NJ/MP) are shown next to the major branches. Labels of terminal branches are written as "taxon abbreviation (population code-number of individuals/number of clones)". For taxa abbreviations, see Table 1.