What are all of Maine's plants?

Answer 1

The USDA keeps a nearly comprehensive list of all the plants living in the US. See plants.usda.gov. Click "state search" on the left side of the screen, check the box next to Maine, and click "search" at the bottom. This will produce a very long list of plants that grow in Maine, including native and exotic species. You can also do a more specific search by going to "advanced search" on the first page and specifying a county in Maine or a type of plant.