Many higher plants have been introduced, mostly unintentionally during the sealing and whaling periods near to the settlement at King Edward Point. Hairy bittercress has been recently introduced accidentally at King Edward Point and efforts are underway to eradicate it before it spreads uncontrollably and affects indigenous species. Meadow grass was probably introduced at numerous sites during the sealing era in the 19th century, and is currently the only alien species widely distributed around the island.
Most of the introductions have resulted from seed inadvertently imported from Europe with foodstuffs for poultry, sheep, cattle and pigs that provided a food supply at several of the whaling stations. A few plants have been introduced accidentally from the Falkland Islands.
About 30 of the identified 70 introduced species survived for only one or a few years. Around 40 have survived several decades, and about 25 of these are now regarded as naturalised. They are reproducing successfully and spreading within and sometimes beyond the whaling stations. Since the mid-1980s many seedlings have appeared around several naturalised species, indicating an increase in fertile seeds possibly in response to warming summer temperature.