Antarctic Floristic Kingdom

The Antarctic Floristic Kingdom (also Holantarctic Kingdom) is a floristic region first identified by botanist Ronald Good (and later by Armen Takhtajan), which includes most areas of the world south of 40°S latitude. The Antarctic plant kingdom includes the continent of Antarctica, Patagonia (southern Chile, southern Argentina, Tierra del Fuego), most of New Zealand, the New Zealand Sub-Antarctic Islands, and all islands of the Southern Ocean south of 40°S latitude, including Gough Island, the Kerguelen Islands, and the Falkland Islands. Tasmania is omitted since its plant species are more closely related to those found in the Australian Floristic Kingdom. Good noted, as had Joseph Dalton Hooker much earlier, that many plant species of Antarctica, temperate South America and New Zealand were very closely related, despite their disjunction by the vast Southern Ocean. The flora of this kingdom dates back to the time of Gondwana, the southern supercontinent which once included most of the landmasses of the present-day Southern Hemisphere, though it has been influenced by the flora of the Holarctic Kingdom since the Tertiary.

According to Ronald Good, about 50 genera of vascular plants are common in the Antarctic plant kingdom, including Nothofagus and Dicksonia. Takhtajan also made note of hundreds of other vascular plant genera scattered about and isolated on islands of the Southern Ocean, including Calandrinia feltonii of the Falkland Islands, Pringlea antiscorbutica of the Kerguelen Islands, and the megaherb genera of the New Zealand Sub-Antarctic Islands.

According to Takhtajan, 11 families are endemic to this kingdom: Lactoridaceae, Gomortegaceae, Hectorellaceae, Halophytaceae, Francoaceae, Aextoxicaceae, Tribelaceae, Griseliniaceae, Misodendraceae, Alseuosmiaceae and Donatiaceae.