Whipcord Hebes - systematics, distribution, ecology and evolution

The genus Hebe (Scrophulariaceae) includes 10 species known as whipcords or Flagriformes. Analysis of DNA sequences supports three distinct groups, ea ch with characteristic chromosome numbers and morphology. There is little s equence divergence within these groups, which reflects rapid evolution, per haps within the last 500 000 years. Two groups comprise montana species of the eastern South Island with chromosome numbers of n = 21. The first inclu des only H. cupressoides, which diverged early from most other hebes. The s econd includes H. salicornioides, H. armstrongii, and H. annulata. The thir d group of whipcord hebes is the largest, has n = 20, and is subalpine-alpi ne. It consists of H. tetragona and H. hectorii which occupy the wetter mou ntains along the axial ranges except for a gap of 320 km in central Westlan d, H. lycopodioides and H. imbricata which occupy drier South Island mounta ins, and H. propinqua which grows in the south-east of the South Island. H. ochracea from western Nelson appears to be an allopolyploid hybrid between members of the second and third lineages. Based on these results, the foll owing new combinations are made: Hebe hectorii subsp. hectorii, H. hectorii subsp. subsimilis, H. hectorii subsp. coarctata, H. hectorii subsp. laingi i, H. hectorii subsp. demissa, H. hectorii subsp. subulata; H. lycopodioide s subsp, lycopodioides, H. lycopodioides subsp. patula; H. imbricata subsp. imbricata, H. imbricata subsp. poppelwellii.