Abstract The origins of the mountain flora of New Zealand are discussed, particularly in relation to a recently expressed view that some of the most important genera arrived in late Pliocene-Pleistocene times via the Australian mountains, where they are represented by a few species, and have subsequently shown vigorous speciation in New Zealand. Such an origin generally does not accord with available information on taxonomy and distribution (e.g., in Celmisia, Hebe, Ourisia, Gentiana), or the evidence is equivocal (e.g., Epilobium, Olearia); nevertheless, origins are clearly Australian in others (e.g., certain epacrids). Despite the prevailing westerly winds at very high altitudes, opportunities for east to west dispersal exist in the lower-atmosphere circulation around anticyclones, and in flights of birds. Bird migration paths and disjunct distribution of some graminoids attest to the probability of occasional direct dispersal to New Zealand from the Northern Hemisphere. Pre-glacial Antarctica must also have been a major source for New Zealand mountain plants. The alpine flora of New Guinea, on the other hand, is younger and there are few indications that it has contributed to Australasian alpine floras, either primarily or as a “stepping stone” from Asia. Although much of the New Guinea alpine flora is derived from Australia, there is no evidence for direct exchange with New Zealand. On the other hand, close similarities between forests in New Zealand and at high altitudes in New Guinea result from northward spread of “austral” elements and southward spread of “Malaysian” elements. There is not enough evidence to indicate whether this interchange took place along former and existing links through the south-west Pacific or via the Australian mainland. The prevalence of white flowers in New Zealand is mainly a feature of the rapidlyevolved mountain flora. Coloured flowers characterise many species with peripheral or restricted distribution, especially on outlying islands. It is suggested that such species are largely relict from the Tertiary flora of New Zealand, which was depleted by the PlioPleistocene mountain building and climatic changes. At the same time these events stimulated the rapid evolution of alpine plants, some of which subsequently dispersed to the Australian mountains.