Assembly of Australia’s alpine seed plant flora

A total of 327 sequestration events were identified that led to the creation of 534 native Australian 534 native Australian alpine plant species in 62 families. Of these events 76% resulted in only one species, 13% were followed by minor radiations (144 species), and 10% were ambiguous (142 species) and may have involved multiple sequestrations. The latter and convergent evolution mean that the count of 327 events may be an underestimate. The alpine flora are dominated by groups that arrived in Australia long after the break-up of Gondwana (at least 62% of the species and 54% of the sequestration events), and mostly appear to have reached Australia by trans-oceanic dispersal. However, most of these recent events involved the intermediate step of occupying non-alpine habitats prior to colonising alpine habitats (at least 46% of these events and 53% of the species). Most of these latter groups mostly came from Africa, but Eurasia and the Americas also contributed. Groups that arrived directly from other regions mostly appear to have come from New Zealand. Alpine Tasmania, especially western Tasmania, has more old Australian groups, including remarkable palaeoendemics, and more woody species than alpine mainland Australia.