<p>Phylogeographic studies of Aotearoa New Zealand plants have largely focussed on lowland trees, with herbs and alpine plants less well studied. Here, we examined the chloroplast phylogeography of taramea, speargrasses, <i>Aciphylla</i>, a large radiation of herbs mostly endemic to New Zealand. <i>Aciphylla</i> contains morphologically diverse species that occur from sea level to alpine habitats. Our focus was <i>Aciphylla</i> from the South Island, the centre of species diversity, but we also included specimens of the related genera <i>Anisotome</i>, <i>Gingidia</i> and <i>Scandia</i>. None of the four genera was monophyletic in our chloroplast network. <i>Aciphylla</i> and <i>Anisotome</i> formed a related cluster of haplotypes with some haplotypes shared between the two genera as well as between species within genera, which likely results from chloroplast introgression. Moderate genetic differentiation was detected but very little of the chloroplast variation was partitioned by species or genus. Haplotype diversity and endemism was high across the South Island, indicating widespread in situ survival across the island during the last glacial maximum including in the central South Island, a region thought to have been heavily impacted during glacial periods. Co-occurring haplotypes were not always each other’s closest relative, indicating the survival of significant levels of diversity, through multiple glacial cycles. Multiple hybridising species may have acted as a reservoir for chloroplast diversity, enabling the persistence of haplotypes as species shifted ranges and changed in abundance in response to past climate fluctuations.</p>