Evidence for an indigenous pre‐quaternary element in the mountain flora of New Zealand

Summary Cool climates and plants adapted to them are usually considered to be of very late Tertiary or Quaternary origin in New Zealand, but there is evidence of much greater antiquity in a number of genera and subgeneric groups which are small and taxonomically isolated, restricted to cool habitats, and either endemic to New Zealand or occurring elsewhere only in the Australian or American sectors of the South Temperate Zone. There are also three groups of podocarps with claims to belonging to the same ancient cool‐climate element, in that their cool‐climate species appear to be older tnan those occurring under warm‐temperate conditions. Since it is unlikely that such plants entered the mountain flora during the Quaternary, whether by trans‐oceanic immigration or by evolution from warm‐climate Tertiary ancestors, it is suggested that suitable environments existed during the Tertiary as cold, wet, infertile soils on peneplained uplands. The species of this element are characteristic of such soils at present, as components of vegetation similar to that growing in corresponding habitats in southern Chile and Tasmania. On the other hand, younger, better‐drained soils at high altitudes support a distinctively New Zealand vegetation, comprising a wealth of species which probably resulted from rapid evolution during the Quaternary era.