St. John’s-wort is introduced in Southeast Alaska. While it is an invasive plant in many regions, to this point it does not seem to have made in-roads around Sitka, as I have only noticed it growing at the edge of the long term parking at the Sitka airport. It will be interesting to see what happens with it over the next couple of years, as it may have only recently been introduced here (though it’s been reported at other locations in Southeast for many years).
St. John’s-wort (Hypericum perforatum) at Natural History of Southeast Alaska wiki