Ana, Good day, and thank you for using Ask an Expert. Your mystery plant may belong to the Apiaceae family which contains dill, parsley, St. Catherine’s lace and much more. Unfortunately, I’ve been stymied in a search for its name.
But I can say that it’s not on Oregon’s list of invasive plants. Even so, I suggest you make a decision as soon as possible about whether or not you’ll keep it. Once those flowers set seed, you’ll have thousands of its progeny to deal with next year and beyond.
Resources for you:
- Oregon Invasive species: 100 most dangerous invaders to avoid http://www.oregon.gov/oisc/Pages/most_dangerous.aspx#Land_plants
- Portland’s Invasive Plants (a poster) http://www.portlandoregon.gov/bes/article/98648
- Garden Smart Oregon (Alternatives to non-invasive species) http://www.nature.org/ourinitiatives/regions/northamerica/unitedstates/oregon/howwework/gardensmart-oregon.xml