On 12 May the ships anchored at Christmas Harbour for two and a half months, during which all the plant species previously encountered by James Cook on the Kerguelen Islands were collected.
[5] Large floating forests of Macrocystis and Durvillaea were found until the ships ran into icebergs at latitude 61° S. Pack-ice was met at 68° S and longitude 175°.
Hooker dedicated it to the local naturalists Ronald Campbell Gunn and William Archer, noting that "This Flora of Tasmania .. owes so much to their indefatigable exertions".
Hooker's Flora Tasmaniae was "the first published case study supporting Charles Darwin’s theory of natural selection".
[7] It contained a "milestone essay on biogeography",[8] "one of the first major public endorsements of the theory [of evolution by natural selection]".
While he asserted that "my own views on the subjects of the variability of existing species" remain "unaltered from those which I maintained in the 'Flora of New Zealand'", the Flora Tasmaniae is written from a Darwinian perspective that effectively assumes natural selection, or as Hooker named it, the "variation" theory, to be correct.