Fig. 2From: Natural hybridization and asymmetric introgression at the distribution margin of two Buddleja species with a large overlapHaplotype networks for gapC1 (a), gapC2 (b), defA (c), fl1 (d) and nrETS (e). Pink, blue and green circles represent haplotypes of B. officinalis, B. crispa and their putative hybrid. Small red circles represent hypothetical or unsampled haplotypes. The number of mutations separating two haplotypes is indicated by the length of the connecting lines unless the number was shown on the lineBack to article page