Maximum parsimonious (50% majority-rule consensus) trees of the PgiC gene. a. For the diploid species Achillea setacea and A. asplenifolia only based on 29 consensus sequences and 14 equally most parsimonious trees (tree length = 212, CI = 0.6415, RI = 0.9007). b. For all the studied diploid and tetraploid species and populations based on 109 consensus sequences and 7840 equally most parsimonious trees (tree length = 508, CI = 0.3484, RI = 0.8909). Bootstrap supports (>50%) from MP/NJ analyse are shown above/below the major branches. Label for the sequence (terminal node) is written as "taxa abbreviation # population code (number of individuals/number of clones)". Abbreviations: asp = A. asplenifolia-2x, set = A. setacea-2x, col = A. collina-4x, mixA = mixed populations of A. asplenifolia-2x and suspected A. asplenifolia × collina-4x backcross individuals, mixS = mixed populations of A. setacea-2x and suspected A. setacea × collina-4x backcross individuals. c. Proposed scheme of incomplete lineage sorting of the PgiC gene. Species are outlined by thin solid lines; alleles A1, A2 and A3 are represented by dashed, thick solid, and dotted lines, respectively.